Recent Advances in Industrial Machines and Mechanisms

Multi-state mechanical devices (MSMD) form a class of mechanical devices that has the capability of changing their topological structure under different operating states. In literature, a gap exists in providing a causal explanation for how a MSMD’s intended function is realized through its structure and behaviour. This work attempts to adapt and integrate various features of existing structural representation methods with SAPPhIRE—a model of causality and aims to develop a systematic method for constructing SAPPhIRE models of MSMD. This provides a foundation for creating a functional modelling scheme that can provide a comprehensive and rich description of a MSMD.

Railway vehicles form a major form of transportation in India and their operations have been in place for more than a century. In the recent past, emphasis has been given to improve the safety and the speed of the railway vehicles. This calls for realistic modelling and analysis of railway vehicles, for which many software applications exist. However, these are all primarily developed outside India and hence a need for an indigenous analysis software exists. In this paper, an attempt to develop an in-house railway dynamics analysis software in the form of RailAnalyzer has been reported. In the current scenario, kinematic and dynamic analyses of an isolated wheelset have been implemented. It allows the user to choose dicone wheelset on tangent knife-edge, and cylindrical rails, and also the actual wheel profile of S1002 and rail profile of UIC60. The analyses results can be seen in the form of animation of 3D model of the wheelset motion on the rails and also has options to view graph plots. The future versions envisage to model the other systems such has bogie, carbody and full train.

Vehicle ride comfort is a key and important parameter which defines customer perception, reliability, and creates a brand image. In an electric two-wheeler, analysis for ride comfort is more important as the conventional engine is replaced with a battery pack and motor, thus changing the source of vibrations. In the case of electric vehicles, “road-induced” vibrations are the key source of rider discomfort. This paper focuses on developing a virtual simulation-based methodology for suspension tuning and optimization. The complete methodology is divided into two phases. In Phase1, analytical 1D model is built for the identification of vehicle suspension characteristics through a sensitivity study and optimized for multiple road profiles to achieve the ride comfort values as per ISO 2631-1. In Phase2, a detailed two-wheeler multi-body model is built to validate the selected suspension parameters and to study the vehicle ride dynamics. The vehicle ride quality is evaluated by vibration dose value (VDV) calculation which defines the ride comfort index over a continuous exposure of vibration for 8 h and compares it with the ISO 2631-1 standard. Optimization is carried out to determine the possible suspension parameters tuning to achieve the optimal ride comfort values.

In this article, a performance investigation of a low-speed high torque hydromotor drive system used in blast hole drilling machine is carried out for varying load conditions. Blast hole drill machines are widely used in drilling operations in open-pit mines to drill hole in rocks. During such operation, the varying strength of rocks results in variable load on hydromotor, which decreases its speed and it may lead to fluctuations in speed as well as torque. A high torque low-speed hydromotor is used to fulfill the requirement of operation, which has lower volumetric efficiency than its counterpart. As a result, such hydromotors have more leakage losses with an increase in the load on it. Therefore, a constant speed of the drill bit of said machine is needed for smooth operation. In the present work, a PI controller is used to vary the pump displacement that manipulates the supply flow to the hydromotor in order to maintain a constant drive speed irrespective of load. In this respect, a Simulink model of the drive is developed, and a test rig is fabricated to validate the system responses. The test rig consists of a loading unit that replicates similar varying load conditions on hydromotor as it experiences with the variation in the strength of the drilled rock. The obtained results indicate an improved performance of the hydromotor drive used in the blast hole drilling operations by implementing the said controller.

Onboard a satellite, a Video Monitor Steering Mechanism (VMSM) is used to capture the video of an on-orbit operation. VMSM is steered about a single axis. The key elements of VMSM would be camera, motor, balancing mass and a mounting bracket with feedback system. Cooperative design of balancing mass ensures gravity centre of rotating mass coinciding with rotation axis which helps in static/dynamic balancing of mechanism during launch by reducing the disturbance torque about rotation axis. VMSM is developed as a compact, miniaturised system actuated by a back driving resisting motor. Together with the back-driving torque of the motor and minimal centre of gravity eccentricity, it prevents the rotation of camera during launch and thus avoiding a separate launch restraint system. The system should meet the required fundamental natural frequency in launch configuration. Analysis has been carried out to estimate the initial frequency of the system and to enhance it further to meet the stiffness requirements. Iterative normal mode analysis technique is used to increase the frequency by adding stiffeners at appropriate locations and removing material at non-load paths. Further, margins are estimated for stresses and loads in the components.

Recursive Dynamics Simulator (ReDySim) is a tool for the dynamic analysis of multibody systems. It has high computational speed, and most importantly, it is freely available. ReDySim is built on the computationally efficient and numerically stable dynamic formulation named Decoupled Natural Orthogonal Complement (DeNOC). This paper focuses on enhancements to the existing Graphical User Interface (GUI) of the Recursive Dynamics Simulator for multibody systems. The enhanced GUI is developed on MATLAB app designer and takes input from the user to perform the analysis. Originally, it was developed in the form of MATLAB codes only. Due to the difficulties in editing the model parameters, the necessity for a user-friendly GUI arose. As a result of which, a primitive GUI version was developed. Now, the GUI is enhanced in a more user-friendly environment by taking feedback from the users of various academic institutes. The enhanced version of ReDySim GUI is discussed in this paper. An overview of the current version of ReDySim GUI is presented here, while the improvements from the earlier versions are mentioned explicitly. This current version includes an analysis of more robotic systems than the earlier version. A proportional-derivative control has also been added the along with the existing forward and inverse dynamics analysis. The current version can be downloaded from http://home.iitj.ac.in/~surilshah/redysim.php .

This article presents the non-dimensional natural frequency of a thin elliptical plate lying on an elastic substrate. The Winkler-type elastic foundation has been assumed for the study. The plate under consideration is subjected to hygrothermal environment. The plate’s edges are assumed to be under two separate edge constraints: simply supported and clamped. Classical plate theory in conjugation with Rayleigh–Ritz approach is used to derive and solve the governing equations. To satisfy the different boundary conditions, algebraic polynomials are utilized. In this presented mathematical method, the essential edge constraints have been satisfied rather than considering the natural edge constraint, and based on the obtained admissible functions, the displacement is defined. The described technique has the benefit of being able to handle every combination of edge restrictions effectively, even in the presence of an external environment. In order to validate the suggested model, the non-dimensional natural frequencies computed by the current process are compared with those found in the available literature. The non-dimensional frequencies of elastically supported elliptical plates with varying aspect ratios, edge limitations, and foundation parameters have been reported after convergence and comparison. The reported results show that the non-dimensional frequency increases with an increase in aspect ratio of the plate.

In this paper, a control system is designed for a path following problem of a flight-type underactuated autonomous underwater vehicle (AUV) operating in a vertical plane. Initially, a guidance law is formulated based on a desired path tangential angle and vertical cross-track error. The guidance law generates the pitch angle reference for the pitching motion of the vehicle such that the cross-track converges to zero. A pitching control system is constructed based on the extended state observer-based controller (ESO) for the AUV to track the commanded pitch angle value with stern deflection angle as a control input. The resulting diving motion drives the AUV to reach and follow the reference path. For the purpose of evaluating the effectiveness of the control system design, numerical simulations are conducted.

A data-driven modeling approach has been proposed in this paper where the state space of the whole hydraulic system is estimated from the measured input and output data. Both the traditional (TSID) and parsimonious subspace identification have been used in estimation process, and one trade-off is observed between TSID and PARSIM that TSID is a more efficient estimation algorithm where no step change occurs, but with a step change in response, PARSIM estimates both efficient and robust estimation in finite and asymptotic sense.

This paper aims to elaborate a technique to solve the inverse kinematics problem (IKP) of a general RRPRRR serial link manipulator which turns out to be the general case of the Stanford arm robot. Although the IKP of the Stanford arm is well established in the literature, solving its general form is not a trivial problem. The contributions of the paper include elaborating the solution procedure based on the Raghavan–Roth formulation and viewing the root finding process as a polynomial eigenproblem rather than a normal or generalised eigenproblem. In fact the structure of the equations are such that it leads to a quadratic eigenproblem formulation which opens up the scope for broader analysis in the future. It is well-known that the upper bound on the number of solutions would be 16 in the complex plane and the same has been elaborated in this paper through an appropriate example.

In this paper, a three-link rigid-flexible manipulator has been designed and developed for high-speed operations. The manipulator features one prismatic joint and two revolute joints to obtain the three-dimensional workspace. Before fabrication of the real setup, CAD (computer-aided design) model was built, and analysis was done to get an optimized structural design. Both the rotating links can translate together in vertical direction using the prismatic joint. The motor for the second rotating link is placed on the main structure, and a belt was used to transfer the rotation, which makes the experimental setup unique compared to those available in the literature. The full workspace analysis of the fabricated setup is done experimentally and theoretically. The setup is fabricated for high-speed operations while minimizing the vibrations. The motors inputs are PWM (pulse width modulation) signals and angle required to turn. The workspace is traced at very low speed to avoid deformation effect. The tip acceleration while rotating first link to 90 degrees by varying the PWM is also obtained using both rotating links attached.

Several sources for excitation of high fluid pressure pulsation and hydraulic pipeline systems can produce pipeline system vibration failures due to overload in the engineering sector. This article is the study of pressure pulsation on two different hydraulic systems, simple and regenerated hydraulic systems. The pressure pulsation observed in both systems was different for the different loading conditions. Simple hydraulic systems reduced the frequency of pulsation with an increase in the load, and on the other side the regenerative system increases the pulsation frequency with an increase in load. This informs that at higher loading conditions the pressure pulsation attenuation will be difficult in the regenerative hydraulic system.

The automated operation of Unmanned Aerial Vehicles (UAVs) has become increasingly important, and one key step in the procedure is the accurate landing of such vehicles. A major problem is that when trying to design a control algorithm for the landing procedure, it is difficult to accurately measure the 3D pose of the vehicle with respect to the local environment. Three dimensional pose estimation and subsequent corrections in velocity to design the control system was omitted by using an image-based visual servoing controller. Another important development is choosing the appropriate visual features which ensures convergence to desired position. The proposed controller with image moments as features was able to converge and land the vehicle accurately using only the image moments as the visual features from two fiducial markers without any local position or global position information. The proposed method has been verified using simulations considering an existing model of UAV.

In modern technological systems, the primary concern is performance, safety, and dependability. As a result, a reliable supervision platform that includes fault detection and isolation is useful to avoid malfunctions or failures. As a result, fault diagnosis is very helpful to the hydraulic system’s safety and dependability. This chapter discusses a unified method for bond graph model-based quantitative Fault Detection and Isolation. Several Fault Detection and Isolation (FDI) techniques all universally accept the Bond graph model [1–7].

As the human hand is a biomechanical system, its function and motion can be replicated artificially as a mechanical system. Mechanical hands can be used to perform dexterous tasks performed by humans in an environment unsuitable for humans, or as prostheses, etc. In doing so, a user interface like a man–machine interface is required to control the development of motion of the mechanical hand. One such method uses surface electromyography (sEMG). The sEMG signals can be modeled to predict intended movement. The work presented here is focused on developing three blocks namely the mechanical design, intent analysis, and movement control block. To this effort, a 16 degree of freedom (DOF) mechanical hand is designed. The intent analysis is done using regression neural network. For the movement control block, an embedded system is developed to detect sEMG signals and generate control signals for the actuators of mechanical hand. Overall in this work, all three blocks are integrated to develop a design of a sEMG-controlled mechanical hand.

In the dual-probe heat pulse (DPHP) sensor we have developed, a voltage pulse is applied to the heat probe across a powder-coated ultra-thin nichrome wire that is wound on a thin copper rod encased in a steel tube. The rise in temperature measured by an adjacent thermocouple probe is used to estimate the volumetric soil-moisture content because heat capacity of the soil is largely influenced by the moisture in the soil. The focus of this paper is on semi-automated manufacture of the DPHP sensor. In the current method of prototyping of the sensor, manual winding of the powder-coated nichrome wire in a double helix around the copper rod is tedious and the nichrome wire is prone to breakage or loss of insulating powder coat. Furthermore, soldering of the nichrome wire along with the connecting wires on the solder pad is time-consuming. The semi-automated double-helical winder mechanism developed in this work makes use of two stepper motors, while the solder setup is foot-pedal-controlled and has the soldering iron attached with two motorized solder wire feeders.

Previous works have experimentally demonstrated that Bridge Configured Winding (BCW) suppresses unbalanced magnetic pull (UMP) in electrical machines with offset rotor. This work attempts to evaluate BCW’s passive control ability in the mitigation of UMP in a cage motor with an oval stator. The simulations were performed on a four-pole cage induction motor with an oval stator by assuming that the rotor and the stator are concentric. A time-stepping FEM code developed in MATLAB platform has been used for the study. Different degrees of ovality in the stator have been considered to study the influence of BCW in reducing UMP. Fast Fourier transform analysis has been used to predict the identifiable frequency components of UMP in the asymmetric air gap.

Each continuum robots have a more flexible and bendable structure than conventional manipulators. This makes it suitable for operating in narrow and deep surgical spaces. This chapter presents a control framework for position control of the three-segment tendon-driven continuum robot. The framework includes kinematic control in configuration space with null space optimization of robot configuration, kinematic constraints, and disturbance in joint space during the tracking process. The presented framework has been successfully simulated to regulate the position error to near zero also can compensate for the joint level disturbances in the form of tendon length variation due to buckling and friction.

Pneumatic actuators operate with various nonlinear forces acting on them, such as the stribeck frictional effect, variable frictional coefficient across different positions, momentary compression of air, slippage due to lack of lubrication, irregularities in the air supply tubes, the dead-zone effect of valves, time-varying friction, etc. Thus, position control of pneumatic systems becomes challenging as control logic like proportional-integral-derivative (PID) controllers starts to lose quality under such a highly disturbed environment. A high amount of un-modelled dynamics results in an irregular response of controllers across different stroke positions. This paper models a pneumatic system and advocates using the continuous integral sliding mode control (ISMC)-based approach to control piston positions accurately. Sliding mode controllers use high-frequency switching control, hence having limited practical usability. ISMC controller is a combination of two controllers, one a discontinuous control which creates a perturbation-free environment for the nominal control working alongside. Continuous ISMC replaces the discontinuity in ISMC with a continuous term, thus having great potential for practical use. A small and crisp sensor unit comprising one position sensor and two small pressure sensors is used. To best utilise resources, other physical parameters are accurately estimated by the software using advanced sliding mode-based approaches like uniform robust exact differentiator (URED) [14], hence keeping a tap on the cost of the proposed solution. Continuous ISMC uses sliding mode control to eradicate all disturbances in the system, hence providing a disturbance-free controller like PID or LQR to control the system variables. The paper presents results from both simulations as well as actual hardware setups. The hardware setup includes a double-acting pneumatic piston and two 5/2 E-P proportional flow control valves. A pair of power amplifiers supply current to the E-P valves. A Control system running in a Python environment sends digital signals to a Digital to Analog Converter (DAC); an analogue output from the DAC then controls the output-current controller. The DAC works alongside the AT90USB1287 microcontroller, which provides the additional utility of acquiring pressure sensor readings using an on-chip ADC. Robust and accurate control of pneumatic piston caries is a massive advantage as pneumatic actuators are low cost, spill-free and environment friendly.

In this chapter, a dynamic analysis of a low-speed, high-torque gerotor motor drive system is performed under varying load-condition. These drive systems are predominantly used in heavy earth moving machineries, construction machineries and industrial applications where high torque is required. As the load increases, the angular velocity of the gerotor motor decreases due to the decreased volumetric efficiency of the hydraulic components. To compensate the increased leakage losses, the prime mover speed is controlled using an artificial neural network-based fuzzy PI controller in the present research work. The fuzzy PI Controller, varies the constant gain terms of the PI controller with the variation in the error signal. Such controller provides a large control signal to reduce the error signal initially and it reduces the Kp and Ki values continuously as the error signal approaches to the zero. To fulfill the above requirement of continuously varying PI parameters, the fuzzy method is used that interpolates the variables from input–output data-set using the assigned fuzzy membership function. The fuzzy membership functions of the controller are trained and rules are optimized through an artificial neural network. The control strategy adopted controls the discharge given to the gerotor motor, which drives the gerotor motor at a constant speed regardless of the load. In this regard, a Simscape model is developed for the given control configuration and verified on the test rig. Using the said controller, a constant speed gerotor motor drive is achieved irrespective of the loading on the gerotor motor and successfully implemented on the test rig.

This paper presents modeling of interaction between a multi-fingered hand and object in precision grasp. The analysis is useful in planning of precision grasps with dexterous multi-fingered hand and can be extended to the study of precision manipulation by robotic hands. We develop the grasp matrix given the coordinates of the contact points and normal direction at the contact points. The grasp matrix computes the resultant force on the object given the contact forces. We also develop the hand Jacobian for the multi-fingered hand that maps the joint torques to the fingertip forces. We present the modeling for a three-fingered hand and an arbitrarily shaped object. We present the condition for force closure and the method to evaluate it for grasping by a multi-fingered hand. We also present the additional conditions required for grasp by underactuated hand. This work extends our previous work in which we considered grasping of cylindrical objects. We extend the work to arbitrarily shaped objects in the present work.

Cable-driven continuum robot (CCR) is a class of flexible robots in which the robot is deformed by pulling a set of inextensible cables. To improve the dexterity of this robot, multiple robotic segments are stacked serially on top of each other to form a multi-segmented CCR. One method to solve the forward kinematics of a single-segmented robot is to use the optimization-based method, which is derived from the principle of minimization of strain energy density. In this paper, the optimization-based method is extended to predict the profile of a multi-segmented continuum robot. For a multi-segmented robot, the distance between the backbone and the cable pairs of each segment is different. Hence, the mathematical model is modified to account for the same. In order to validate the model, a series of experiments was conducted on a 300 mm long robot prototype which uses Nitinol (NiTi) rod as its backbone and nylon threads for actuation cables. The optimization-based model is solved using the fmincon routine in MATLAB, and the solution is superimposed on actual deformation profiles. The mathematical model predicts the profile of a multi-segmented CCR for in-plane bending as well as out-of-plane bending with RMS errors of 1.3% of CCR length and 4.2% of CCR length, respectively. It was found that the proposed model could also predict the deformed profile of a multi-segmented CCR in contact with the obstacle, with an RMS error of 1.1% of the CCR length.

A continuum manipulator can theoretically have an infinite number of shapes for the desired end-effector pose. Taking the advantage of this behavior, this paper proposes the reconstruction of the shapes of a pneumatically actuated continuum manipulator under the effect of hysteresis to avoid collision with any obstacles present in the target trajectory. At first, a trajectory is selected from the workspace of a continuum manipulator. Subsequently, the required optimum actuation pressures for each tube of the pneumatically actuated segments are determined by using a two-way neural network model. The resulting pressure sets are then used as input to a forward kinematic model of the continuum manipulator developed based on the Cosserat-rod theory. This includes nonlinear constitutive relations based on the fractional-order Bouc–Wen model for the representation of material hysteresis behavior. The model is validated on portable bionic handling assistant, which is a pneumatically actuated continuum manipulator. The combination of the artificial intelligence model for inverse kinematics with an explicit mathematical model for forward kinematics results in greater positional accuracy in the presence of obstacles in the manipulator path.

Titanium and its derivative alloys have multiple and wider applications in the field of additive manufacturing, aerospace engineering, biomedical industries, chemical industries, etc. Biocompatibility, high stiffness, high specific strength, low density, etc. are the properties that enable its vast use in different industries. Furthermore, its application in the field of abrasion and wear and tear-like situations is due to its low hardness, and high wear rate-like properties. After its failure, it must be superseded, but this adversely cause heavy cost to the industries. In this regard, different researchers are modifying the surface of titanium alloy. So that it can withstand the harsh condition and cut the cost of industries. The major intention of this work is to obtain a hard coating on titanium alloy using WC + Cu + La2O3 as the electrode material through the reverse EDM processing route (also known as electric discharge coating). The electrode is prepared using a hot mounting press and the coating is made under the reverse polarity of EDM with distilled water as a dielectric fluid. Coating layer thickness (CLT), Tool wear rate (TWR), Material deposition rate (MDR) and microhardness are the recorded output responses. 325 µm of maximum coated layer thickness is obtained at 11 A peak current, whereas, the maximum microhardness of the coated layer is noted as 726 HV0.1 at 13 A current which is twice that of the substrate Ti–6A–4V plate. MDR increases with a rise of peak current up to 11 A thereafter it starts decreasing because high spark energy remelts the earlier solidified coating layer. TWR increases with a rise in peak current as a consequence of higher spark energy between the electrodes.

Wire arc additive manufacturing (WAAM) is a metal-additive manufacturing process that uses electric arc as the heat source to melt metallic wire available as feedstock and deposit it layer upon layer to form a 3D object. This comparatively cheaper additive manufacturing technology than other additive manufacturing processes can manufacture medium-to-large size components at a higher material deposition rate that can be reached up to 10 kg/h. However, the major limitation of this process is to deal with complex heat configurations that prevailed during the material deposition. Modeling and simulation of the WAAM process provide an efficient way to detect such challenges and provide ways to reduce them. In this research work, simulation of the WAAM process has been carried out using Simufact Welding software for 316L stainless steel material. The components designing and meshing have been done by using MSC Apex software, and the famous Goldak double ellipsoidal model was used for simulating the moving heat source. The simulation have been performed for total four-layer deposition. The obtained thermal cycle through simulation result shows the same pattern as the available experimental results in the previous literature.

Electrode polarity in electro-discharge machining (EDM) is vital in distributing discharge energy to the workpiece and the tool. Currently, powder-mixed dielectric application in EDM is an emerging field to improve machining efficiency and achieve better surface quality and surface modification. The current investigation implements straight and reverse polarity for machining titanium grade-5 alloy using urea-mixed deionized water dielectric in Maglev EDM. The machining operation has been performed on a titanium grade-5 alloy workpiece (15 mm × 15 mm × 3 mm) using a cylindrical mild steel tool (ø = 3.3 mm). The parametric conditions for the investigation were discharge voltage (20 V) and discharge current (160 mA) for both straight and reverse polarity. The dielectric fluid is prepared using urea mixed with deionized water at a concentration of 75 g/l. During straight polarity, an average MRR of 148.5 µg/min and average TWR of 30.5 µg/min were achieved by using the powder-mixed dielectric. In reverse polarity condition, an average MRR of 69.5 µg/min and TWR of 97.5 µg/min were achieved using the same dielectric concentration. Maximum erosion was observed at the anode for both polarity conditions. Additionally, the surface characteristics of the machined workpiece have been examined using SEM micrographs and EDX reports.

The complexity of welding Mg alloys using conventional welding can be overcome by using friction stir welding (FSW), by virtue of its solid state joining process. In the present study, two Mg alloy plates were welded using the FSW technique. FESEM image shows that both the plates were joined effectively without any internal defects such as porosity, voids, and tunnelling. EDX reveals that there was the formation of an oxide layer on the stir zone (SZ) which helps to increase the hardness value at the SZ and was obtained to be greater than the base metal. An optical microscope (OM) reveals the fine and equiaxed grain microstructure in the stir zone because of dynamic recrystallization. Coarser and elongated grains are present in TMAZ and HAZ. Furthermore, micro-hardness obtained at stir zone was more than the base metal. The obtained result shows that FSW of Mg alloy can be a promising method to produce lap joints with improved microstructure and mechanical properties. Moreover, FSW can be employed to join dissimilar materials. FSW is adapted in additive manufacturing process to build parts (as functionally graded materials) layer by layer of dissimilar materials.

Burr formation is inevitable in micromachining, nevertheless, it can be minimized in several ways. Rake angle is one of the most influencing tool geometrical factors affecting the micro-burr formation, especially in orthogonal machining. The present study has been focused on the prediction of exit burr formation in orthogonal micromachining varying the rake angle of the cutting tool. Finite element modeling has been applied to predict the burr formation using Abaqus software. Three different rake angles have been used for the FE modeling those are 0°, − 15°, and − 30°. Machining has been performed on aluminum alloy Al7075. The results of the FE modeling precipitated that the exit burr width was maximum for machining with 0° rake angle followed by − 15° and − 30°. For validation of the FE modeling, experiments have been carried out using uncoated tungsten carbide cutting tool. The rake angle has been varied accordingly and exit burr formation has been measured. The experiments have shown well similarity with the simulated study. It has been observed that the height of the exit burr was maximum for − 15° rake angle. Eventually, the exit burr formation can be minimized using a higher negative rake angle without compromising with specific cutting energy in orthogonal micromachining.

Sustainable advanced manufacturing is an excellent alternative to the conventional approach to minimize (or) eliminate the hazardous effects of commonly used dielectrics in EDM. In the current research, the machining characteristics of Ti-6Al-4V alloy have been investigated using neem oil and canola oil as plant-based bio-dielectrics in Maglev EDM. The machining operation is conducted on a Ti-6Al-4V alloy workpiece (15 mm × 15 mm × 3 mm) using a cylindrical mild steel tool (ø = 3.3 mm). Material removal rate (MRR) and tool wear rate (TWR) have been evaluated for both bio-dielectrics. The results were compared for respective bio-dielectric at discharge voltage (22 V), discharge current (200 mA), and duty cycle (95%) for every experimental repetition. The voltage–current (V–I) waveforms analysis depicts stable and consistent pulses with minor irregularities. The obtained results show an MRR of 147.5 µg/min in the case of canola oil and 125.33 µg/min in the case of neem oil. Similarly, a TWR of 1.32 times higher was achieved using canola oil as compared to neem oil. The SEM micrographs and EDX reports help analyze the machined surface characteristics by observing the surface anomalies and material migration effect.

Laser beam welding (LBW) is an advanced welding technique having high-power density and a small focal spot that has been widely applied to join multiple metal parts by utilizing the heat generated from the focusing of amplified coherent light photons known as LASER. LBW is extensively used to join dissimilar metals and alloys in offshore structures, pipelines, aerospace, shipbuilding, power plants, and tool and die industries because of advantages like controlled heat dissipation, smaller weld bead formation and minimal heat affected zone (HAZ). However, the dissimilar metal joining process tends to form a brittle intermetallic compound (IMC), leading to solidification cracking in the weld bead, thereby reducing the dissimilar joint strength and making the process of joining dissimilar metals a challenging task. The current work explores the basic phenomenon in different weld zones and their influence on dissimilar laser-welded joints. An overview of the dissimilar laser welding of materials such as aluminium, titanium, and stainless steel, along with the development of major techniques to reduce IMC formation, has been presented.

In the present study, friction stir welding (FSW) is used to join different materials with distinct thermo-mechanical properties, such as copper (Cu) and aluminium (Al) 6061 alloy. The produced lap joint was characterized in terms of topographical, morphological, chemical, and mechanical characterization using the 3D profilometer, energy-dispersive spectroscopy (EDS), and field emission scanning electron microscopy (FESEM). 3D images show that there is no surface defect such as flushing during the fabrication of lap joint. The FESEM micrographs were taken at different magnifications. Weld nugget zone (WNZ) shows the mixing of Al and Cu and it produces a composite-like structure. The EDS spectra show the presence of elements such as Al, Cu, and oxides at the interface of two layers. Further, tribological results show that the average coefficient of friction value for weld zone, Cu plate, and Al plate are 0.125, 0.309, and 0.473, respectively. The weld zone shows an improvement in the frictional behaviour and COF value is reduced by 3.5 times compared to the Al alloy. The results indicate that FSW can be a promising route to joint dissimilar materials with enhanced properties.

The Cobalt-based L605 super alloy have been considered for the laser welding purpose due its wide application in defence technology, aerospace, gas turbine and industrial furnace and liners in high-temperature kilns. So, this chapter focus on the similar laser welding of L605—Co-based super alloy sheets. The process parameter like laser power and scanning speed on weld top and bottom width, micro hardness, HAZ and welding strength of the weld joints were investigated. As the scanning speed increases, the top and bottom width reduces to minimum and power of 1600 W and 400 mm/min are the near optimum process parameter for the fabrication of sound quality of weld. The hard phase like CrCo are observed at the weld zone which enhance the micro hardness, which is found to be maximum of ~ 320 HV0.1. The ductile failure of the welded specimen are confirmed from the FESEM analysis, which indicate the presence of dimples, inter-granular cleavage, and micro voids in the fracture zone. The average grain size of the phase formed at the HAZ are 21.52 (µm), it has been observed. The maximum tensile strength (~ 1000 MPa) are found.

Use of current and vibration signal analysis for fault detection and condition monitoring of rotary machines is well understood in literature. However, to perform machine learning driven fault analysis in rotary machines, the entire machine learning pipeline of data collection, cleaning, de-noising, feature engineering, model training and hyper-parameter tuning has to be implemented. Among all these steps, the feature engineering becomes most critical because of multiple reasons. First being the fact that we do not directly incorporate the time series but instead translate it into encoded variables. This can lead to a large explosion of features which in presence of limited data may become an ill-posed problem. Therefore, reduction of features to the most appropriate ones is not only important for developing a simpler model but may become a necessity due to limited data. In this article, various methods of feature engineering have been deployed based on the underlying machine learning model. It has been found that there are several features that are common irrespective of the underlining model. The article provides a discussion on the possible reasons for the specific subset selection.

Vibration signatures are routinely used for condition monitoring of rotary induction machines. The sources of vibrations can directly be traced to the mechanical state of the machine. Thus, providing a direct link to its health. Nonetheless, collecting vibration data may not always be feasible due to accessibility constraints or because of the presence of other sources of vibrations and noise in the environment. Therefore, the last couple of decades have seen a development of electric current-based condition monitoring for such machines. Therefore, in this article an attempt has been made to illustrate how the two modalities relate to one another. A relational map from electrical (current and voltage waveforms) domain to mechanical (vibration) domain is proposed. This relational map can then be exploited to setup a transfer learning-based process to utilize electrical measurements (current and voltage) and use them to classify faults, usually best detected in mechanical (vibration) domain.

Rotating equipment, including generators, motors, pumps, and turbines, frequently employ rolling element bearings. Primary reason for failure in rotating machinery is bearing failures. Early bearing fault diagnosis is essential for avoiding machinery breakdown. In general, condition-based maintenance is used to prevent bearing failure. The vibration signal of a rolling element bearing with a localized fault shows periodic impulses. The bearing fault vibration signal is feeble at the early stages of the bearing fault. Present work uses zero-frequency filter and wavelet transform-based algorithm for early detection of the bearing faults. The present work aims to check the noise robustness and reduction in aliasing using various mother wavelets vibrations caused by bearing faults. Using a simulated noisy signal containing periodic impulses, the algorithm is explained. Results from various mother wavelets, such as the Symlet, Coiflet, and Daubechies, are compared using the de-noising algorithm with two levels.

Maintenance Management Techniques have changed enormously with the advent of predictive maintenance methodologies or the so-called condition-based maintenance (CBM) or condition monitoring (CB). Both dynamic (Vibration/Sound) and tribological (Oil analysis) signals play a major role in maintenance of machinery and plants. The conventional time scheduled maintenance (periodic monitoring) has been found to be uneconomical, whereas in new CBM technique, many advantages are seen including cost effectiveness. For implementing this new technique of CBM especially for large plants requiring huge investments on diagnostic equipment, any management would prefer to get convinced prior to implementation. This paper deals with this object to develop an effective mathematical cost model (MCM) based on data already collected for machinery and prove its effectiveness by applying this model to some major industries such as aviation and shipping. In both cases, it has been shown to use MCM as an effective model for implementing CBM for many other plants also. Ultimately, this model helps to introduce newer techniques in maintenance management such as pro-active and reliability-centered maintenance and avoid all older techniques so far followed. Most of the modern machinery today are already applying all these new concepts to prevent failures and increase the safety and operation of all vital machinery, where both men and machines involved. The cost model developed in this paper helps considerably to arrive at major decisions in implementing these new techniques in maintenance management.

This paper develops and compares a methodology for gearbox fault diagnosis based on calculus-enhanced energy operator (CEEO) and machine learning. This paper used three directional, i.e. X, Y, and Z, vibration signals of a bevel gearbox to classify the gearbox faults. Therefore, three directional, i.e. X, Y, and Z, vibration signals of a bevel gearbox were extracted based on three different speeds and loading conditions. Then, the raw vibration signal from all directions was pre-processed using CEEO. Next, the CEEO vibration signal was used to compute twelve time features for all directional vibration responses. Afterwards, a random tree (RT) and J48 were used to select the significant time features. Lastly, five different types of neural networks were used to classify the gearbox fault based on specified time features of RT and J48. A comparative assessment of the classification accuracy for gearbox fault diagnosis is also presented. The results showed that the RT performed significantly better than the J48 for gearbox fault classifications based on CEEO vibration signals.

Rolling element bearings (REBs) are the commonly used components of rotating machines such as rotors, turbines, motors, and pumping systems. Faults in REBs induce periodic impulses. The faults may lead to improper operation of machines and breakdown of rotating machinery. Preventive maintenance requires the early identification of bearing defects. The present work provides a combined method for detecting bearing faults based on the Hilbert envelope (HE) and the continuous wavelet transform (CWT). The CWT with Coiflet wavelet of order one is used for the analysis. Hilbert envelop removes the high-frequency oscillations from the vibration signal. The periodicity of these impulses is detected using CWT to obtain the bearing characteristics, fault frequency and harmonics. The wavelet analysis is a convolution of the signal and the mother wavelet function that has been dilated and translated. Wavelet transform possesses unique characteristics for extracting irregularities from a noisy signal. The wavelet transform (WT) examines a signal into various frequencies at different resolutions. In the present work, the CWT coefficients are obtained by selecting a suitable range of scaling. The scalogram of the CWT coefficients at a suitable range of scales is plotted. A comparison is made between the CWT scalogram of the input signal with and without the HE. CWT of the HE output gives precise peaks corresponding to the fault frequencies. The number of harmonics corresponding to the defect frequency is more in the case of a CWT with the HE. These harmonics give a clear picture of the fault in the scalogram. The present work is demonstrated using a simulated bearing fault signal and experimental bearing dataset.

Gears are important part of rotating machineries for power transmissions. Faults in gear of machineries can lead to failure of machineries. It is thus important to monitor the conditions of gears to prevent break down of machineries. Modelling of machine is a virtual prototype which can be used to generate a large amount of data and can easily replace the expensive part of analysis of the system by using experiments. In this article, a model of epi-cyclic gear train is developed using multibody simulation software to study the effects of fault in its vibration responce. Here, missing tooth is created in the sun gear of epi-cyclic gear train. Design of gears is done using Catia V5. Different design and constraints between different subsystems is modelled using a multibody dynamics simulation software (MBS ADAMS). The simulated signal is then processed by Hilbert transform to obtain its envelope to remove the structural noise. Finally, FFT is done to get an inference of the condition of gear. The system’s Gear Mesh Frequency (GMF) is determined from the gear kinematics. In the envelope spectrum, high amplitude of peaks at GMF is observed in faulty as compared to healthy epi-cyclic gear train which manifests its health.

Electrical submersible pumps (ESP) are the classification of hydraulic pump that is applicable to transport fluids from submersible elevations toward a fixed pipeline. Submersible pumps are commonly put to use in several areas such as domestic utilization, city water supply, irrigation system, and extensive industrial applications. Therefore, it is estimated that a significant portion of total electrical grid energy is consumed to run the electrical submersible pump. Hence, in the case of a faulty electrical submersible pump, the consumption of total grid energy increases. For the economic growth of any country, it is very important to understand the different failure mechanism, which arises in the electrical submersible pump, and also it is necessary to find out the root causes of these ESP failures along with proper mitigation methods to avoid these kinds of failures. Although electrical submersible pumps are being used for many years ago, it is still suffering from many failures, and these failures can be summarized into three major kinds of failures, i.e., electrical failures, mechanical failures, and operational failures. This review paper deals with a comprehensive study based on ESP failure mechanisms and a proper analysis of these failures for the determination of optimum conditions. It is found that among these failures, electrical failure is a very severe form, and suitable equipment and material can reduce this. Mechanical failure is mainly dependent on the material of the equipment; hence, the equipment should be corrosion resistant and compatible to avoid these kinds of failures. Operational failure is mainly dependent on the nature of the processing fluid. The processing fluid can be a single phase (only liquid), two phases (liquid and solid), and multiphase (liquid, solid, and gas). Failures due to multiphase fluid are more significant than that of others.

Induction motors (IMs) are the prime movers for the industries. The availability of an efficient electrical drive has aided in the widespread application of IMs in different sectors, including mining, cement, textile, and many more. Bearings are the critical components of the motors. The bearing failure may cause severe accidents and production losses. The timely detection of the bearing fault is essential for the minimum downtime. Researchers have used conventional machine learning techniques for the bearing fault detection in motors. However, these approaches require input features, and selecting efficient features poses a big challenge. Deep learning (DL) algorithms have recently captured the interest of researchers all over the world. DL algorithms like convolutional neural networks (CNNs) can automatically execute feature extraction and selection. This paper proposes a hybrid CNN-based model in combination with support vector machine for bearing fault detection in IMs. Various bearing faults, such as inner race fault, outer race fault, and ball defect, have been considered in the proposed work. The proposed method has efficiently detected various bearing faults. The proposed approach has achieved a mean accuracy of more than 99%. Python was used for all of the analysis and programming.

This article investigates the static behaviour of a rectangular isotropic plate having two different types of porosity, namely even porosity and uneven porosity. The plate is subjected to different combinations of mixed edge constraints, viz. simply supported, clamped, and free. The behaviour of static parameters (α, β, and β′) associated with bending and normal stresses has been studied for the plate under different loading conditions, namely uniformly distributed load (UDL), and sinusoidal load (SL). Classical plate theory (CPT) has been used during the course of analysing the static bending of the plate and the governing differential equations have been derived by using the energy principle. The Rayleigh–Ritz method with an algebraic polynomial has been used to solve those governing differential equations. This mathematical formulation presents simple, accurate, and computationally quick numerical results. The convergence of static parameters has been obtained by increasing the number of polynomials of the displacement function. To validate the proposed model, the static parameters calculated by the current technique are first compared to the available literature. The effect of aspect ratios and porosity volume fraction on static parameters has been comprehensively explored for different boundary conditions. Numerical values of static parameters are higher for porous rectangular plate than that of nonporous rectangular plate. The effect of aspect ratios on the static parameters of porous rectangular plates has also been examined. As the aspect ratio raises, the value of static parameters also increases because the plate becomes less stiff as the aspect ratio increases. It is also observed that the free edge constraints have higher value of static parameters, whereas clamped edge constraints have the least. The results obtained from this study can be used for future reference.

The effect of embedded delamination on the free vibration behavior of variable stiffness composite laminates (VSCL) has been investigated in this paper. The FSDT is applied to formulate the FE model of the plate using eight-noded isoparametric elements. Hamilton’s principle is used to obtain the governing equation. A region-wise model is implemented to mathematically express the centrally located square delamination. Both symmetric and unsymmetric laminates under various boundary conditions have been considered to examine the consequences of different delamination parameters (size and position) on the eigenfrequencies. Natural frequencies of the plate get reduced in presence of delamination due to the degradation of structural stiffness.

The present work represents a finite element method (FEM) based computational technique to predict the first-ply failure (FPF) load of delaminated thin cantilever composite conical shell under rotation. An eight-noded isoparametric shell element is employed based on Mindlin’s shallow shell theory, which includes the effect of transverse shear deformation. Multi-point constraint procedure is used to model the delaminated shell. Different first-ply failure theories like Maximum Strain (independent), Maximum Stress (independent), Maximum Stress (polynomial), Tsai-Hill, Hoffman and Tsai-Wu are used to estimate the FPF loads for both stationary and rotating shell. The precision of existing process is compared with available benchmark results. Outcomes of the existing work includes the effect of some important parameters like different delamination zone, rotational speed, aspect ratio and fiber orientation angle on FPF loads.

The fibres are used in numerous operations because they are exceptionally stiff, robust, and light. The tensile modulus of carbon fibres ranges from 207 to 1035 GPa; low modulus fibres having a lower density are less expensive and have stronger tensile and compressive strengths than high modulus fibres. A mixture of graphitic and amorphous carbon makes up carbon fibres in their structural state. The corners of interconnecting regular hexagons are where the carbon atoms are positioned in each layer of the parallel planes or layers that make up the crystallographic structure of carbon. In contrast to the binding between the planes, which is held together by weak van der Walls type forces, there are strong covalent bonds between the carbon atoms in each plane. Since carbon fibres are commercially accessible on the market for applications involving weight reduction, their high cost is not taken into account. The authors of the current work used finite element analysis to perform a Hashin failure analysis on a carbon-fibre-reinforced composite. Understanding fibre composite fracture under the influence of various forms of force is provided by Hashin failure criteria. To investigate the theory of fibre failure in composite materials, a carbon fibre composite was subjected to tensile and compressive loads of 500 N.

A two-step seed-assisted hydrothermal approach was used to grow CuO nanostructures (NSs) on the surface of woven carbon fiber (WCF) by treating in two controlled chemical precursors, namely seed solution and growth solution. The controlled growth of different shapes of CuO NSs was created by tuning concentrations of precursor solution at 120 °C for 12 h of growth period. Different morphologies were examined on scanning electron microscope, energy-dispersive spectroscopy analysis, and X-ray diffraction techniques. The results demonstrated that the duration of growth treatment and numbers of seeding treatments have a substantial impact on the formation of CuO NSs. On increasing the formation of CuO NSs, the height of X-ray diffraction peaks of CuO crystals enhances as well. Developed CuO-modified WCF samples were used to fabricate laminated hybrid composites using epoxy resin as matrix by vacuum bagging technique. The fabricated laminate was examined on Charpy impact testing setup which discovered that they had a significant increase in impact energy absorption capability. The formation of CuO NSs can reduce composite delamination because of the enhanced surface area generated between the matrix and the fiber, and variation in the convergence of CuO NSs will cause the modification in the impact energy absorption capacity.

Modal analysis and dynamic analysis are performed in the proposed work to determine the implant’s natural frequencies and critical cross sections using numerical analysis. The femur bone and implant model are designed using CT-scan data and SOLIDWORKS software, respectively. This model is imported into ABAQUS for free and fixed vibration analysis. The analysis is done for natural bone, stainless steel (SS) 316, cobalt-chromium (Co-Cr) alloy, and titanium (Ti) alloy. On a typical human prosthetic hip, this work performs a load based on patients weighing 102 kg. At the implant’s loading location, a critical activity-bearing 28.8 N m moment and a high peak load of 4200 N are introduced for analysis. The modal and dynamic analysis results are compared for different biocompatible materials. Natural bone has much lower modal frequencies than the SS 316L material. The Co-Cr and Ti alloy modal frequencies are comparable to the femur’s natural bone material. The best material for making implants is titanium alloy because it is lightweight, lesser von Mises stress and higher deformation for the same load, boundary conditions, and loading position in comparison with other materials.

In recent years, cases of paralytic attacks have significantly increased. Consequently, disability arising due to paralytic attacks has surged. In such circumstances, the patients are confined to their beds, and even self-lifting the bed seems to be an impossible feat. In order to enable the paralytic bedridden person to control their medical bed without the need for physical effort, a novel method was introduced. The paper describes the development of electroencephalography (EEG)-controlled pneumatic-actuated hospital beds enabling the patient to raise the height of the bed just by thinking of raising or lowering the bed. These pneumatic actuators in the hospital bed employ air as a fluid medium. Because air is compressible, it produces a cushioning effect that gives the system an extra benefit. The method employs a brain–computer interface, which enables direct communication of the brain with the pneumatic control system of the hospital bed using EEG signals. These signals are the name given to the tiny impulses in the form of fast currents and spikes sensed within the network of neurons in the human body. These EEG signals are acquired from the neuro headset and transmitted to a personal computer wirelessly. The complete workflow of the system can be explained in three stages. In the first stage, the headset acquires the EEG signals, which are then transferred to EEG signal processor. The EEG signals obtained are converted into readable data, then trained using machine learning (ML) to encapsulate a person's thought into the output signal completely, thereby enabling the actuator to move up and down based on these thoughts. Subsequently, these data are processed in the browser-based node-red programming environment. In the second stage, the logic is developed in the node-red environment, where all the systems are integrated. The logic filters the data into defined categories and then sent as the desired output to data acquisition board (DAQ). The board converts the obtained digital input into analog output. In the third stage, the output signal of the DAQ board is amplified using a power amplifier. The power amplifier controls the airflow rate in a proportional valve and consecutively actuates the pneumatic cylinder, thus enabling the patient to control the height of their medical bed without any physical contact.

The joint that joins the temporal bone to the jaw is called the temporomandibular joint (TMJ). Daily oral functions like speaking, eating, chewing, mastication, and many more are controlled by this joint. Numerous musculoskeletal conditions known as temporomandibular disorders are caused by the overloading of this joint (TMDs). This review sought to evaluate the approaches put out by various researchers in the literature for treating temporomandibular problems (TMDs). To determine the reasons behind the suggested methods for the corrections or treatments of TMDs patients, a thorough review was conducted. According to the literature, research used a significantly lower sample size to create techniques for TMDs correction, therefore therapies may not have worked for all TMDs patients. Based on the TMDs, a total of 39 related research works were found, and after applying exclusion and inclusion criteria, 8 full-text papers were included in this report. The literature's suggested treatments or approaches required a long enough time to rectify ailments, which finally caused suffering for the patient. Exclusively, a small number of researchers have put forth an efficient treatment method, however they have the drawback of only treating one specific form of TMDs. There is no proven approach described in the literature for treating all TMD types. To address the problems with this joint, a deeper comprehension of the temporomandibular joint’s biomechanics is required. This thorough investigation will pave the way for the creation of quick, efficient, and preventative TMD treatment methods.

The current study proposes the dynamics of a biological membrane in response to electromechanical stimuli considering the mass of the membrane. A membrane’s dynamical aspect is particularly challenging to analyse due to its complex structure and changing material properties. Furthermore, the presence of an electric field affects critical aspects of biological membranes such as thickness, density, tension and curvature. The effect of the electric field on the membrane’s thickness is considered for the current analysis. The membrane is modelled as a dielectric sandwiched between electrodes to demonstrate the electromechanical coupling. Fung’s exponential material model is employed to depict the membrane’s nonlinear elastic behaviour. The governing equation for the system is then derived using lumped parameter model. The analysis is presented in terms of two dimensionless force parameters. The variation of these parameters shows changes in the corresponding dynamic behaviour. The proposed work will aid in demonstrating the dynamics of the biological membrane under the influence of an electrical field for bio-mimicking applications.

We present a computational study of Prandtl’s secondary flow of the first kind in the presence of turbulence within a 90˚ in-plane double bend fitted between two straight ducts. Most of the previous papers available in the literature demonstrate the gross flow behaviours due to out-of-plane double bends. We, however, focus on capturing the local flow behaviours in an in-plane double bend and the progressive development of the flow downstream of the bend. We capture a pair of Dean vortices located downstream of the double bend. We trace the motion of higher velocity fluid particles within the vortices by in-plane velocity vectors directed from the pipe core towards the bend’s outer side due to an unbalanced centrifugal force of the skewed flow. Our solutions nicely capture the decay of the in-plane flow (or secondary flow) and concurrent re-establishment of primary flow downstream of the bend. For engineering analyses, we introduce a new parameter called enhancement ratio ( $$\varepsilon$$ ε ), a measure of the increase of the fluid velocity while passing through the bend. $$\varepsilon$$ ε decreases with increasing both Reynolds numbers ( $${\text{Re}}$$ Re ) and curvature ratio ( $$\overline{R}_{c}$$ R ¯ c ). It is realized that the reduction of $$\varepsilon$$ ε is related to the corresponding fall in non-dimensional pressure loss.

Many geometrical and experimental methods were proposed to enhance heat transfer in a heat exchanger. This paper emphasizes improving heat transfer in elliptical ducts compared to conventional circular, square ducts. Simulation results using Ansys showed that the length of the duct required to obtain the desired temperature difference for elliptical ducts is lesser than that for circular and square ducts. The energy balance method was used to obtain differential equations solved using MATLAB. Simulated results in Ansys Fluent were reported for the ducts under consideration. Fluid in the ducts is of high temperatures, where the mode of heat transfer through radiation is substantial. For elliptical ducts, temperature gradient vs. aspect ratio and temperature gradient vs. time at constant aspect ratio graphs were plotted. The maximum pressure for elliptical ducts was 0.362 bar, whereas, for circular and square ducts, it was observed to be 0.3801 bar and 0.4978 bar. The maximum temperature for the elliptical ducts was observed to be 372.4 K.

Numerical simulations of coal combustion of two samples with varying ash content are performed in a drop tube furnace (DTF) to mimic the particle heating rates observed in industrial furnaces. The combustion performance of high-ash Indian coal is explored through particle tracking and mass fractions of various products of combustion. Inferences are drawn about the role of varying ash content on the overall combustion performance. It is found that the high-ash content coal sample has a tendency to produce less $$NO_x$$ N O x and enhanced combustion performance, as it falls within an optimum ash percentage range.

Computational fluid dynamics (CFD) is one of the advanced numerical tools used to simulate multiphase fluid dynamics problems for various scientific applications worldwide. Many commercial and open-source CFD software are available for simulation, ranging from simpler to highly complex phenomena. This research paper has compared the simulation of coal dust dispersion in a 20 L explosion chamber using two established commercially available software, viz Ansys and Fluidyn. For this simulation, the laboratory experimental properties of the coal sample, i.e., Narsamunda coal mine, ECL was taken. The turbulent kinetic energy (TKE) and velocity vector are important parameters for optimum dispersion which is a required condition for an explosion phase. The simulation results of both the software are similar when compared with TKE and the velocity vector of coal dust particles for the dispersion phase. The explosion study was carried out in a 20 L explosion chamber with CFD software (Fluidyn), and the severity of explosion has been determined for the coal sample, i.e., Narsamunda coal mine, ECL.

The current study presented a coupled thermo-structural and steady-state thermal analysis of an array of solid and porous fins subjected to two-dimensional convection inside a rectangular enclosure. The study investigated the heat transfer parameters, such as the Nusselt number, heat transfer coefficient, fin surface temperature, and thermal stresses of inline and staggered fins (solid and porous). An in-depth examination of the inline and staggered fin configurations demonstrated that the staggered arrangement provided better performance up to Reynold number 8000. However, once the Reynolds number was increased over this threshold, both configurations exhibited similar performances. The outcomes of the study revealed that the configuration of the fins had a significant impact on the Nusselt number and coefficient of heat transfer of porous fins. However, the effect of the fin arrangement had little impact on the average temperature of the porous fin. Furthermore, the thermo-structural analysis revealed a significant amount of thermal stresses generated at the joint of the fin and base. Thus, care should be taken while designing, arranging, and selecting the fin material to keep the generated stresses within the yield strength of the material.

This study comprises a performance analysis and stress analysis of the helical Darrieus hydrokinetic turbine (HDHKT), considering the turbine’s solidity by varying the number of blades. Primarily, in order to conduct performance analysis, numerical investigation of three- and four-blade HDHKTs are designed in SOLIDWORKS software and to be evaluated in ANSYS CFX software. Secondly, stress analysis is performed for the selected turbine in ANSYS static structural based on the performance analysis. For this analysis, the cross section of each blade for all the turbines is considered as NACA 4421 as it shows best results due to the optimum blade thickness. For the performance analysis, different operating conditions are considered in which free-stream velocity is considered 0.5 m/s for each number of blades. The obtained results suggest that with an increase in solidity, starting torque increases, corresponding to the operating condition. The highest coefficient of power was obtained at four-blade HDHKT at the solidity of 0.25. Moreover, obtained results from the performance analysis suggest that four-blade HDHKT performance is best. Further, numerical analysis is conducted by selecting four-blade HDHKT for the stress analysis in the ANSYS static structural, considering free-stream velocity 0.5‒2.0 m/s. For the analysis mentioned above, the obtained hydraulic loads from the ANSYS CFX are further subjected to ANSYS static structural domain to obtain the stress values and strength of each HDHKT. The results obtained from the stress analysis suggest that the four-blade HDHKT having solidity of 0.25 shows better results and can sustain hydraulic loads at the desired operating condition. The maximum von-Mises stress values for the varying free-stream velocity 0.5‒2.0 m/s for solidity 0.25 is 26.36 N/mm2, 67.72 N/mm2, and 70.32 N/mm2, respectively. Therefore, four-blade HDHKT having solidity of 0.25 is selected as best performing and capable of bearing hydraulic load.

This paper presents the tribological and dynamic performance characteristics of ellipsoidal dimpled textured EHL concentrated line contacts. The simulated investigation involves coupled solution of incompressible Reynolds lubrication equation considering cavitation, elastic deformation, and rheological effects. The performance parameters (pressure profile, film thickness, frictional coefficient, contact dynamic stiffness and damping coefficients) of the textured line contacts have been evaluated and compared with conventional contacts at the sets of input data. The results reveal substantial increase (10–38%) in minimum film thickness and significant reduction (16–50%) in frictional coefficient with textured contacts.

Present work investigates the performance of different pad-shaped sliders (cycloidal, polynomial, exponential, secant, hyperbolic, and plane). Performance of hydrodynamic lubrication is altered by considering surface roughness along with couple stress. In a mathematical model of the slider bearings possessing surface roughness which is a stochastic random variable with mean (≠ 0) and variance (≠ 0) in analysis. The rheological characteristics attributed to the lubricant with polymer additions are described by Stokes which is based on couple stress model of fluid. For couple stress fluids, in regard to the Stokes micro-continuum theorem, for the general lubricating film shape, updated expressions for bearing pressure, load carrying capability, center of pressure, power loss coefficient, and frictional force are produced. Dimensionless couple stress parameter is used to analyze the performance of slider bearing under the influence of couple stresses. With respect to surface roughness parameter in both Newtonian and couple stress fluids, bearing performance parameters are examined. Moreover, couple stress fluids exhibit these effects in a more pronounced manner than corresponding Newtonian fluids. It is noted from the current study that the exponential-shaped slider outperforms other pad-shaped sliders in terms of performance.

Excellent hardness and toughness of zirconia toughened alumina (ZTA) ceramic composite make it worthy to fabricate the parts for defense, aerospace and bio-implants industries. But machining of ZTA in acceptable tolerance is challenging due to its improved properties. In this paper, optimum values of variable factors for multiple hole quality characteristics are evaluated using genetic algorithm. Multiple hole quality characteristics include circularity and taper of laser trepanned hole in thick ZTA. The overall improvement is found approximately 33%. Further, optimum results are verified with confirmation experiment that shows small variation of 4.89%.

Supply chains are emerging trends across the globe, and the response time of any good supply chain is dictated by managing the vehicle routing across its chain. The recent supply chains like the big basket and Swiggy depend upon efficient vehicle routings. The current paper efficiently cuts down the transit time by optimizing the travel routes within each supply chain hub. The problem can be best explained as a HUB and Spoke mechanism. The hub represents the warehouse, and the spoke represents the various routes devised for delivering to the customer. The paper addresses the different delivery boys needed for efficiently delivering the goods to the customer in minimum time, thus improving the response time of supply chains. An ant colony optimization is designed to minimize the response time of the different supply chains.

A special tool is developed to explore the possibilities of handling multiple sub-assemblies simultaneously, outside the core of a fast nuclear reactor. The tool is developed in response to enable a safer and speedy handling of sub-assemblies in a test facility. The design of the tool is as per standard design codes and procedures, and provisions are provided in the tool to accommodate pitch errors in the arrangement of sub-assemblies. The tool also encompasses engineered features for fail safe handling and to ensure safety during the operation. This paper discusses the conceptual design of the new tool, its design features, the performance testing, and qualification under simulated conditions.

This research article presents the design, 3D modeling, and finite element analysis of traction elevator wire ropes. The main objective of this study is to reduce wire rope failures and enhancement of safety features as per industry standards. Two different configurations of the elevator wire rope have been studied in this study. Design calculations have been carried out for both the configurations and 3D modeling has been done using SolidWorks. Further, the analysis part has been carried out using ANSYS. From this study, it can be concluded that the newly configured design of wire rope has shown better toughness and resilience as per industry standards. Suitable safety practices have been suggested to mitigate mechanical stresses and hence result in an improved design with the reduction in downtime.

Bias flow acoustic liners are used to suppress thermo-acoustic instability in jet engines. This paper aims to identify the problems associated with the flow noise and the inability of acoustic loads to characterize acoustic liners in the presence of high mean flow. At high mean flow, conventional loads deviate from the criteria of being an effective acoustic load, as flow noise dominates the sound source. Three different loads, an open-end termination, an expansion chamber, and a quasi-anechoic chamber, have been used in the present work. The acoustic parameters absorption coefficient and reflection coefficient are presented to quantify the ability of acoustic loads considered at different mean flow rates. The results suggest the need to design an acoustic load that could absorb flow noise and enables in-duct characterization of acoustic elements in the presence of high mean flow. At the same time, loads must not obstruct the path of flow.

A modified chemo-mechanical model of crystalline silicon nanowire during the first lithiation is presented. Here, we incorporate the kinetics of the addition reaction, thereby mimicking the experimentally observed lithium-rich zone, lithium-poor zone, and the moving interface. Also, this model consists of a strongly two-way coupled diffusion of lithium through the lithium-rich zone. The total deformation gradient is expressed in terms of the elastic, plastic, and stress deformation using multiplicative decomposition. Interface reaction exponents are fitted by adjusting the same parameter so that it reproduces an interface velocity observed experimentally. Therefore, a comparative analysis with the result obtained for spherical crystalline silicon anode particles shows uniform distribution of lithium concentration and a non-hydrostatic state of stress in the lithium-poor zone.

This paper dedicates an analytical computation of vibration and far-field sound radiation of clamped power law index functionally graded plates (P-FGM). This paper deals with uncoupled acoustics and entails a novel approach to computing the natural frequencies, harmonic response, and acoustic response by considering the clamped FGM plate’s physical neutral surface. This work is novel as little research on sound radiation has been carried out using a physical neutral surface. A novel approach of applying surface or nodal velocity (considering all substeps) of the structure as a boundary condition to the acoustic interface is discussed. Four cases segregated on the power law index, n = 0, 1, 5, and 10, have been studied in this research. A more significant frequency substeps are taken to avoid missing any modal contribution in modal and harmonic response analysis. The harmonic displacement response of vibrating clamped FGM plates is calculated analytically in Matlab and fed as an input to the Rayleigh integral code based on Gaussian quadrature to compute the sound radiation fields. The sound radiation field calculated is validated using solid layer-wise modeling using Ansys. It is found that sound radiated by both the methods and results in the literature is in good agreement. It is also found that sound power level increases and radiation efficiency decreases with an increase in the power law index. Thus, it is concluded that clamped mono-ceramic FGM plates act as a good sound radiator.

In this paper, a reference-based model updating technique is presented which produces the measured eigen data as a subset of finite element model (FEM) eigen data and thus enables to predict responses at global modes and other important modes. The measured modes are used as a reference basis and mass and stiffness matrices of the FEM are updated in such a way that the updated model replicates the test results. The measured mode shapes at limited number of points and in limited degrees of freedom (dofs) are expanded on entire FE grid points using modified inverse Guyan reduction method. Subsequently, using the expanded mode shapes, the FE matrices are updated by minimizing objective functions and invoking constraints to retain the symmetry and orthogonality of the updated matrices through Lagrange multipliers. The effectiveness of the proposed updating procedure is demonstrated by considering a L-shaped cantilever plate. The experimental data (simulated experimental data) is produced by introducing error in the eigenvalues and eigenvectors obtained from the FEM model. In this paper, we have outlined a procedure to implement the algorithm described above in a commercial FE software ABAQUS and Python. The procedure was found to replicate the selected simulated modes by updated matrices. The procedure has been demonstrated for up to 10% erroneous modes.

The shin pad is the most crucial piece of protective equipment used in a variety of sports. It aids in the prevention of sprain and, in the worst-case scenario, fracture-related shin injuries. Shin pads are often constructed of polypropylene or polyethylene, as well as some high-resistance materials like carbon fiber, glass fiber and Kevlar. Years ago, the planning of personalized shin pads began, which resulted in a lack of major material and rigidity advantages as compared to regular ones. The major goal of this study is to figure out if the customized shin pad would be safe from any failure under desired conditions. Furthermore, using finite element analysis, this study examines the approach to the working and manufacturing of commercially used shin pads by finding and modeling the preferred design that is safe under the appropriate stress. This study consists of an explicit dynamics analysis of the shin pad as it is perpendicularly impacted by the cleat of synthetic leather football boots (studs). The range of velocity used in impact analysis is 28–32 km/h, which matches the speed of a football player during tackles.