Advances in Materials, Mechanics and Manufacturing III

Magneto-electro-elastic (MEE) materials have piqued the interest of researchers worldwide due to their high energy conversion rates in the magnetic field, electric field, and elastic field. In this research paper, geometrically nonlinear response of Magneto‐electro‐elastic composite materials (MEE) shell structure is investigated. The proposed finite element (FE) model is based on the Kirchhoff shell theory. A four-node finite shell element is used to analyze and predict the nonlinear behavior of smart structures. Discrete system of geometrically nonlinear equilibrium equations are solved by the Newton-Raphson method. Numerical results of hyperboloid shell are compared with works from literature in order to highlight the feasibility and effectiveness of the current finite element model, notably for thin structures. A good agreement is obtained and the static response of MEE under large deformations and finite rotations. The effect of the volume fraction change of the MEE material on the large deflection of the smart magneto-electro-elastic hyperboloid shell is examined.

The primary aim of this work is to reduce stress within the implant-bone interface by using a unique class of inhomogeneous materials known as functional gradient materials (FGM). To achieve this objective, we have developed a comprehensive three-dimensional model encompassing a dental implant and its surrounding tissue (cortical and cancellous bones). Our study involves an extensive analysis of dental implants constructed from various materials, including both homogenous and FGM substances, using the finite element method. The material properties of the FGM dental implant are precisely defined based on coordinate points within a user-defined material subroutine (UMAT) integrated into the widely-used commercial software ABAQUS/Standard. This approach allows for tailored characterization of FGMs, offering a promising avenue for improving the durability and performance of implant-bone systems. In summary, this research endeavors to enhance the reliability and longevity of dental implants through the innovative application of functional gradient materials and advanced computational techniques.

The development of sheet metal forming products and processes has been mostly influenced by new tools, such as the vast field of numerical investigations based on finite element simulations. Numerical modeling of the material behavior during the forming process is necessary for the quality of the measured results. The characterization and identification of the investigated material data and their transformation into numerical material models are of great importance, especially for the anisotropic sheet metals. In fact, the stress triaxiality, which is determined as the ratio between the average stress and the equivalent stress, presents a crucial parameter in the prediction of ductile damage. In this study, notched specimens with various notch radius are investigated experimentally to capture the ductile fracture of 5083 aluminum alloy, to control their stress triaxiality and to estimate Hooputra’s criterion parameters related the fracture plastic strain with the triaxiality. A VUMAT subroutine containing the numerical material modeling is adopted with Abaqus/Explicit to validate the experimental measurements and a good agreement is obtained, which proves the interest of the suggested model. A numerical study illustrates a valuable guide to predict 5083 aluminum sheet’s behavior deformed by a Single point incremental forming (SPIF) process.

In this paper, post-buckling equilibrium paths of nanocomposite panels reinforced by carbon-nanofillers and subjected to lateral pressure are studied using shear deformable refined theory. Three different types of nanofillers dispersion patterns are considered, including uniform (U-NFLL) and two graded (FG-V-NFLL, FG-X-NFLL) forms. The elastic materials properties of nanocomposite panels are obtained by applying the extended rule of mixture with some efficiency parameters to consider the size-dependency of nanofillers reinforcements. The equations of motion are elaborated within a refined high-order theory which includes seven kinematic variables compromising three displacements: u, v, w and two rotations $${\theta }_{x}$$ θ x , $${\theta }_{y}$$ θ y and two high-order terms of rotations $${\theta }_{x}^{h}$$ θ x h , $${\theta }_{y}^{h}$$ θ y h . The discretization of these variables is established using a four noded finite shell element and the resolution procedure is performed using the Newton-Raphson method with the arc length control technique. The reliability and efficiency of the formulas are validated. The effects of types of nanofillers and their volume fractions on post-buckling behavior of nanocomposite panels are studied and interpreted. It is pointed that graded nanofillers with X-form are more efficient in the enhancement of the post-buckling strength of the nanocomposite panel than other forms with an optimal value of 28% of added nanofillers.

The COVID-19 pandemic has had an extraordinary impact on global supply networks, particularly at the level of the manufacturing system. In this context, a new conceptual framework of assembly line balancing problem called SALBCOVID19P is presented in this paper. The whole product manufacturing workload is distributed among the stations throughout the manufacturing line in an ALBP. Previous research has concentrated on finding efficient and quick solutions for simple assembly line balancing problems (SALBP) and its numerous extensions. Several real-life applications and the necessity to solve exact practical difficulties drive each extension have occurred in the literature. In this article, a new extension of SALBP-1 with constraints related to the COVID 19 pandemic is focused. A mathematical model for Simple Assembly Line Problem Type 1 (SALBP-1) is exhibit with proposed constraints; workstations and workers. The new model of SALBP-1 assumes that each workstation has a minimum length and it exists a minimum distance between two operators. This new extension has been applied to an industrial case.

This research is driven by the overarching objective of assessing and characterizing the intricate damage mechanisms exhibited by glass/epoxy composite laminates, utilizing the acoustic emission methodology. The experimental approach involved the application of static stress to the test specimens, enabling the systematic tracking of various damage modes as they evolved over time. The fundamental aim was to pinpoint the specific damage modes most likely to culminate in the eventual catastrophic failure of the test samples.The identified damage modes encompass matrix cracking, fiber-matrix debonding, delamination, and fiber breakage. These markers serve as critical indicators of structural degradation within composite materials, each offering unique insights into material behavior under varying stress conditions. To derive valuable insights from the acoustic emissions generated during the experimental tests, a robust classification approach was implemented. This involved the synergistic utilization of the k-means method and Principal Component Analysis (PCA), facilitating a comprehensive analysis of the acoustic data. By gaining a deeper understanding of the acoustic signatures associated with diverse damage modes, this research significantly contributes to the broader body of knowledge pertaining to composite materials. These insights hold substantial implications across various industries, such as aerospace and automotive, ultimately enhancing the design, safety, and maintenance of composite structures.

The sheet shearing process is a rising manufacturing technology that has attracted particular attention in industrial engineering like aerospace and automotive. However, a continuous monitoring of process parameters is always necessary to ensure both of the tooling life and the product perfection. This study has led some light in the area of FEA of metallic sheet shearing to avoid locking problem with minimizing experimentation costs. The current work is carried out to develop an-efficient non-associated plastic model integrated with isotropic ductile damage approach in order to improve the numerical procedure efficiency for sheet blanking process. For this purpose, an axisymmetric model is adapted to simulate this process via ABAQUS software code for a lower computational cost. Moreover, the developed model is implemented using user interface material subroutine (VUMAT). The main contribution of this study is to predict the influence of some relevant process parameters such as friction coefficient and punch-die clearance on part quality and to evaluate the capability of the 5083 aluminum metal at shearing deformation.

The lightening of structures is one of the priority ways of reducing the risk of pollution (CO2 emissions). Metal matrix composites present a great interest for the lightening of structures if the improvement of their specific modulus is accompanied by a good strength/ductility ratio. Ferritic steel matrix reinforced with brittle ceramic particles requires the understanding of their behavior under different loading paths for the modeling of their mechanical behavior and for the prediction of their formability. This work makes at a first attempt to homogenize an elastoplastic Fe-TiB2 composite for 12% volume fraction of TiB2 particles and uses for the first time in SPIF manufacturing process. The effective elastic properties are estimated based on Mori-Tanaka model and the rule of mixture. The numerical simulation is done using Abaqus/Explicit. An experimental study from the literature is investigated to validate the elastoplastic behavior of the composite and to estimate the isotropic hardening parameters of Ludwik law. An excellent correlation is achieved between the numerical and experimental stress-strain curves. This numerical study illustrates a valuable guide to predict Fe-TiB2 composite sheet's behavior deformed by a SPIF process.

This paper is dedicated to solving the control issue of a class of discrete event systems with disturbances and subject to Mutual Exclusion Constraints. More precisely, a new analytical approach for designing control laws is suggested to guarantee the satisfaction of these constraints in Timed Event Graph Networks (NTEGs) with some uncontrollable input transitions. This later can be a robot breakdown, a machine supply shortfall, or any other type of machine breakdown or stoppage. For this, Min-Plus linear models represent the dynamic behavior of the disturbed timed event graph, and marking specifications are described by inequalities in Min-Plus algebra. Sufficient conditions to compute feasible control laws are identified according to the initial marking of the considered Petri net. The calculated laws are feedback gains that are represented by monitor places preventing the system from possible violations. To demonstrate the effectiveness and the applicability of the proposed control mechanisms, a case study of a disturbed disassembly system is discussed.

This paper utilizes a specialized solid-shell element with a modified first order shear deformation theory (FSDT) to analyze the linear static behavior of carbon nanotube-reinforced skew plates. The element consists of eight nodes with three degrees of freedom representing the three displacements. Various distributions of carbon nanotubes along the thickness of the skew plates are examined, including uniform and four other functionally graded distributions. To avoid locking issues, the solid-shell element implements the enhanced assumed strain (EAS) approach with an optimal number of EAS parameters, as well as the assumed natural strain (ANS) method. Additionally, the strain compatible part includes a special plot of transverse shear strains to overcome the deficiencies of the shear stress and strain distribution. Actually, there is no longer a requirement for the shear correction factors. The study compares the performance of the modified FSDT-based solid-shell element to other published methodologies in order to evaluate its accuracy in predicting and analyzing the static behavior of functionally graded carbon nanotube-reinforced skew plates.

This present study proposed a study of a multiple-phase change materials-based heat sink. The model was composed of four PCM cavities separated by a 2 mm plate fin. Two heat values were adopted to define the effect of the heat flux over the performances of the single PCM-based heat sink and multiple PCM-based heat sink. Three PCMs: RT44, RT64, and Salt hydrate were tested. First, the performances of the three single PCMs were performed. Then, three pairs of PCMs are studied; Salt hydrate-RT44, Salt hydrate-RT64, and RT44-RT64. The results demonstrated that the low melting temperature PCMs, RT44, and Salt hydrate, showed an efficient performance at the heating phase, benefiting from the early melting of the PCMs. The RT64 revealed a rapid temperature drop at the discharge phase. Consequently, the combination of the salt hydrate with RT44 and RT64 improves the performances of the heat sink at the charge and discharge phases.

A front axle dual tube automobile hydraulic damper is studied using ANSYS software. The study is intended to develop a numerical tool to explore automobile hydraulic dampers behavior. The damper contains two piston chambers (Reserve chamber and Work chamber), one cylinder chamber (Compensation chamber) and two valves (Piston valve and Cylinder valve). The fluid geometry is constructed and the fluid transient regime is analyzed, in compression (Bump) and in extension (Rebound), for a reference piston and cylinder valves configuration. Indeed, the fluid pressure and velocity are visualized, for two reference excitation velocities. The damping force is then determined to plot a force-velocity diagram. The fluid pressure, the fluid velocity, and the damping force, versus the excitation velocity, in compression and in extension, were explored. The maximal fluid pressure, fluid velocity, and damping force according to compression and extension, were tracked. The piston and cylinder chambers pressure in compression and in extension, was highlighted. The fluid velocity at the piston and cylinder valves in compression and in extension, was examined. The results are promising in analyzing and predicting automobile hydraulic dampers behavior in order to cut experimentation costs and to understand the dampers dynamics for better designing.

The demand for advanced machinery and professional mining operations is an Engineering and environmental challenge in Afghanistan. Marble mining generates a tremendous amount of waste; these wastes are deposited in landfills due to a lack of organized waste management. According to previous studies, marble wastes could be used in cementitious structures. Therefore, this research aims to incorporate waste marble in the concrete industry to preserve eco-environmental issues. A comparative study is conducted to replace partially cement/sand in concrete mix design with the exact quantities of waste marble and compared with an industrial product, a calcareous filler supplied by Omya SAS. Marble waste was collected from the mining site of Nangarhar- Afghanistan. The marble waste comprised 29% particle size < 63 μm, and the remaining 71% were sand particles. Mining site waste marble (MSWM) was incorporated at 3.5%, 4%, and 4.5% by the total volume of concrete. Reference concrete was designed to achieve the resistance of C25|30. The outcomes indicate some improvement in the workability and transfer properties of concrete with the increase in MSWM dosage. The optimal dosage of MSWM incorporation that remains concrete strength significantly was obtained for 4%. This dosage corresponds to 7.5% cement replacement and 12% sand replacement.

Hot forming process involves the plastic deformation of metal alloys such as steel and copper to produce pieces. The influence of holding time and isothermal temperature on the microstructure and the hardness of CuZn40Pb2 brass were performed through quenching tests using a thermomechanical simulator Gleeble-3500 that allows water cooling without moving the specimen. The tests were carried out at different temperatures (650 ℃, 750 ℃ and 850 ℃) and holding times (30 s, 60 s and 90 s). Microstructure analysis using Electron BackScatter Diffraction and grain size measures were performed, as well as Vickers hardness tests in the transverse and longitudinal directions. The results showed that the hardness increases with increasing the temperature and the holding time. Up to a holding time of 60 s, the hardness was almost constant in both transverse and longitudinal directions. Therefore, in terms of the microstructure evolution, the average grain size of the non-treated specimen was 27 µm, while the isothermal temperature and the holding time significantly affected the average grain size of the treated specimen. Grain growth was obtained when the holding time and/or the isothermal temperature increase. At a holding time of 60s, the average grain sizes increased from 31 µm to 55 µm with temperatures of 650 ℃ and 850 ℃, respectively.

Composites reinforced with plant fibers are widely used in the automotive and construction sectors. The vast majority is composed of petroleum-based, non-compostable polyolefins, which are no longer a viable solution in an environmental context where the end-of-life management of industrial products is becoming a major societal issue. Here, fully green composites are produced by reinforcing a blend of bio-based and biodegradable matrices, poly-(butylene-succinate) (PBS) and poly-(lactide) (PLA) with flax fiber. In this work, in order to improve the mechanical properties of 80PLA/20PBS formulation-based composite, flax fibers undergo bleaching treatment. The mixing and the injection shaping processes were used to prepare the composite samples.The composites were characterized to investigate the effect of the bleaching treatment in their thermal and mechanical resistance. The control of the adhesion between the matrix and the flax fibers reinforcement and final morphology is studied by Scanning Electron Microscopy (SEM). The results show that the chemical bleaching treatment increases the stiffness, the strength but decreases the strain of flax/ 80PLA-20PBS composite. That means an improvement of the adhesion between the 80PLA/20 PBS matrix and flax fibers. Also, the best performances are achieved with bleaching treatment.

This publication is based on research into the robustness of a complex system. Complexity can be explained by its multi-element structures and deals with the interaction of parameters and investigations. To study the robustness of a complex system, a 12-DDL two-stage spur gear transmission is established. Gearbox systems are characterized mainly by their high noise and vibration levels. We apply the multi-variable uncertainty consideration to examine the dynamic behavior of the gearbox. This study aims to achieve consistent dynamic responses for several purposes, including overall efficiency. This study compares the effect of taking into account the uncertainty to the study of the dynamic transmission ratio of the system compared with its effect on the dynamic behavior of linear displacements as well as the orbital diagrams on the 3 axes of the system.The purpose is to achieve high-accuracy curves arising from taking into account the uncertainty through the probabilistic method of generalized Polynomial Chaos (GPC) and the deterministic method of Monte Carlo (MC). This accuracy enables the proof of the probabilistic results.

Car suspension dynamic behavior under uncertainty is a multidisciplinary field of study that aims to understand and predict a vehicle’s performance in various operating conditions, as well as a complex one since it is a system that interacts with its environment. The robustness of such systems requires a careful understanding of the system design parameters and the parameters of the other interacting systems. Uncertainty in this context refers to the lack of knowledge of the various factors influencing the car’s behavior, such as road profile conditions, tire properties, suspension characteristics, and driver inputs. In this paper, a simplified model of quarter-car suspension was represented. The road profile was defined using an ISO norm. In this study, we examined the impact of a few uncertain parameters on the dynamic behavior of a quarter-vehicle suspension system. The robustness of the design was assessed using two methods, notably deterministic and probabilistic, including Monte Carlo and Polynomial Chaos respectively. The results show a good agreement between these two techniques but with a very different simulation duration.

The efficient operation of electronic products depends primarily on the reliability of the interconnections, provided by tiny solder joints, throughout the life of the product, under real operating conditions. Over the years, the focus has been on the reliability of BGA (Ball Grid Array) components and their geometric and functional optimization. To this end, design optimization is set as an objective. To achieve this target, a sensitivity study of the mechanical response of the BGA component to the variation of the design variables: diameter and height was performed. The criterion of choice for the comparison of these parameters is the number of cycles to failure, resulting from a thermal fatigue study. To apply the fatigue law, a further investigation of the best alloy is conducted. Results showed that although Innolot has minimal plastic deformation, SAC (SnAgCu) is considered the best alloy in terms of reliability and functionality for the longest period. Furthermore, by examining the design variables when the BGA component is subjected to electrothermal cycling load, it is concluded that as the diameter and the height increases, the number of cycles to failure increases, and, thus, large solder joints are the most reliable. This thorough study can greatly help the electronics industry and researchers to decide on the best solder alloys for solder joints and to establish a good environment for the future determination of the optimal geometrical parameters for a BGA component.

This research work is dedicated to the analysis of pressure wave propagation in a non homogenous piping system. The considered system is composed of three pipes; one metallic (elastic) placed between two viscoelastic pipes. The hydraulic system is fed from a water tank and at its downstream side a valve is mounted. The study of the system is based on a mathematical development in which the viscoelastic behaviors of pipe walls are based on the Kelvin-Voigt model. For the numerical modeling, the set of partial differential equations governing the water hammer phenomenon is solved through discretization following the method of characteristics. The propagation of the water hammer wave induced by the closure of the downstream valve is followed up. To illustrate the impact of closing times ranging from fast to slow maneuvers, the temporal evolution of the hydraulic transient simulated at the downstream end of the hydraulic system is investigated for different closing times. Additionally, the effects of the hydraulic characteristics of the system on the wave propagation are studied. Through obtained results, it was found out that the attenuation of the wave is influenced mainly by the mechanical characteristics of the pipe material, its dimensions and the operating time.

All participants in the logistics chain are realizing the significance of minimizing their environmental impacts. Presently, this concept is progressing towards a comprehensive improvement in all links of the supply chain through a principle called the ‘clean supply chain’. In this context, the production process must be more aligned with this direction, shifting from a logic of maximizing productivity towards an alternative that ensures green production, specifically addressing scheduling issues in the production workshops. However, various challenging scheduling problems have been explored in the literature. This paper aims to solve a job shop scheduling problem (JSP) that considers the impact of noise. Optimization of JSP is based on a combination of three objectives: Makespan, energy and noise. The developed model is solved using the particle swarm optimization (PSO) algorithm. The proposed algorithm is tested through a case study. The simulation results indicate the effect of noise consideration in the global affectation of jobs related to JSP. PSO demonstrates his performances in solving JSP considering noise as an objective to attempt.

The study aims to analyze the porosity of Carbon Fiber Reinforced polymer samples produced by 3D printing, with a focus on the impact of printer settings. Specific printing parameters including printing speed, printing temperature and printing orientation are selected. The porosity is calculated as function of measured and theoretical masses and composite density. It is reported that porosity increases by the increase of printing speed. However, it is proved that by the increase of both printing temperature and orientation, porosity turn down to a low value. Experimental tensile tests are performed to study the effect of the obtained porosity on Young’s modulus, so it is revealed that when porosity decreases, Young’s modulus decreases too, only with the increase of printing temperature and printing orientation. Nevertheless, it is demonstrated that when porosity increases, Young’s modulus decreases only when the printing speed increases. The study identified the optimal printing temperature for minimal porosity as 260 ℃, with the highest and weakest Young's modulus obtained at printing orientations of 0° and 45°, respectively.

This attempt focuses on the effects of temperature generation at interfaces when drilling composite stacks associating unidirectional glass fiber-reinforced polymer (UD-GFRP) and aluminum alloy (Al). The thermomechanical properties of GFRP phase combined with disparate properties of isotropic Al phase present several issues for controlling material removal process of such composites. GFRP/Al/GFRP and Al/GFRP/Al stacking sequences were specially considered in drilling tests. The tool geometry and drilling conditions were kept constants during machining. The thrust force, and cutting temperature within both the composite stacks and tool were measured in real machining time. Specially, temperature recordings were ensured using thermocouples TCs preinstalled surrounding the hole to be drilled within the composite stack and within the axis of the drill as well. Thrust force plots obtained within the composite stacks reveal different machining stages to be distinguished by severe discontinuities at interface region between phases regardless the stacking sequence. Unexpectedly, the peak temperature values captured in the tool when drilling Al/GFRP/Al was found more critical than those recorded when drilling GFRP/Al/GFRP while no significant difference was outlined over the thrust force when comparing phase to phase singly. However, temperature history captured within the composite shows increasing flow directed from top to bottom layer regardless the stacking sequence.

Dynamic models of transmission systems have long been used to study the behavior of vibration response and its impact on gear fault detection. This work proposes a method for detecting separated and simultaneous fractures caused by a variation in gear mesh stiffness (GMS) for a dynamic model of a spiral bevel gear system (SBGS) using statistical process control schemes (SPC). Two types of SPC, known as the X-bar chart and an exponentially weighted moving average (EWMA) chart, have been applied. Initially, noise was added to simulate dynamic modeling signal conditions in practice by using different levels of noise variance. Second, the control limits of both X-bar and EWMA control charts are designed using the relative wavelet energy (RWE) computed from the frequency subbands of discrete wavelet transform analysis. Third, the performance of control schemes for separated and simultaneous fracture damage detection is evaluated based on the RWE features of simulated vibration signals under defective conditions. The results of the proposed method indicated that the EWMA chart outperformed the X-bar chart in detecting separated and simultaneous fracture faults at an early stage.

One of the primary types of dynamic loads is random vibration analysis. Composite sandwich materials used in dynamic structures are likely to be damaged due to high acceleration, stress levels, and deformation under dynamic loads. Therefore, it is essential to analyze these materials under dynamic load conditions. In this study, a composite sandwich consisting of two thin skins composed of aluminum bonded to a lightweight core material of PVC foam is analyzed under a random vibration load in the form of white noise. The studied composite sandwich acts as a clamped-free beam and is subjected to PSD G acceleration applied to its fixed edge. Two cases of sandwich composite material were studied, one being the case of an undamaged sandwich composite, and the other being the case of a damaged sandwich composite due to debonding at the skin- core interface. This study has two parts. The first is modal analysis, which is the basis that precedes the analysis of random vibrations through spectral analysis, which constitutes the second part. This work aims to explore the effect of damage by debonding at the skin-core interface on the frequency response of the composite sandwich under random vibration.

The influence of free volume (FV) activation stress on the nanoindentation behaviors of bulk metallic glasses (BMG) Zr65Cu15Al10Ni10 (BMG) was investigated. In this paper, nanoindentation simulations were carried out on samples by the finite element method (FEM) in ABAQUS software using the user-defined material (UMAT), and Berkovich indentation experiments at room temperature were performed on the MG sample at a constant strain rate, to confirm the numerical loading and unloading curves. Based on the measured frictional force by using an atomic force microscope (AFM), we examine the flatness of the tested surface samples to verify the excellent reproducibility of the indentation experiment. The results have shown a good agreement between the experimental and simulated tests. Our simulation results indicated that the FV activation stress has a slight effect on the load-penetration curves. Besides, the plotted contours of numerical data demonstrated that the spatial heterogeneous deformation can be enhanced by severe plastic deformation near the indentation tip. Furthermore, based on the results of the FE modeling contribution, we deduce that the FV activation stress has no remarkable effect on the nanoindentation behavior of Zr-based BMGs, with the exception of a slight improvement in the work hardening of this amorphous material.

Electrodeposition process was used to obtain Zn-Ni coatings on carbon vitreous from sulfate-based bath containing Sn as additive. In order to deposit a fine grained layer containing about 14 wt% in nickel with single intermediate phase, the effect of baths’ parameters (applied potential (E), temperature, stirring and pH)on microstructure and morphology of these coatings, were studied and discussed. The experimental results revealed that increasing the applied potential from −1.4 V to −1.2 V modified significantly the morphology from typical nodular structure to nodules with the appearance of pellets. Then, applying −1.2 V and heating the electrodeposition solution, promoted the single-phase crystallization (δ (Ni2Zn11)which permitted to obtain the inspected smooth fine-grained structure. In order to increase the nickel content, stirring and adjust pH seemed to be a solution. However, stirring during plating involved a cracked surface with 5.5 wt% Ni, adjust pH to 1.7 required the best surface films appearance eby increasing the Ni content up to 16 wt%.

Electrodeposited nickel layers filled with various amounts of graphite or MoS2 particles were prepared on the surface of mild steel substrate (S 235). The weight fractions of solid lubricants in the obtained coatings were determined by atomic absorption. The structural and morphological changes induced by these particles within the nickel matrix were then investigated through X-ray diffraction (XRD), Scanning electron microscopy (SEM), and optical microscopy (OM). It was found that the introduction of lubricating particles had a profound impact on the nickel coatings. In the case of nickel-graphite coatings, while the morphology was transitioned from a pyramidal structure to a local nodular one, nickel-MoS2 coatings exhibited a cluster-like structure. These changes resulted in a more randomized structure and a reduction in nickel grain size. Furthermore, the topographical characteristics of the coatings were assessed using a tactile profilometer. The roughness of the composite coatings increased with higher lubricant particle content, reaching its peak at 29% MoS2 in Ni-MoS2 layers.

Wind energy is an environmentally friendly option to ensure energy security during a period when fossil fuel reserves determine the long-term development of the economy. To improve wind turbines’ ability to produce electricity, blades are becoming larger and more flexible. This increasing flexibility and size of wind turbine blades leads to study their dynamic behavior in order to avoid the fatigue of the structure and consequently its damage. Most of the current research treats linear models built on hypothesis of small deflections. This hypothesis is not applicable anymore for the purpose of designing large flexible blade considering that such structures frequently undergo large deflections. A novel formulation considering geometric non-linearity problems and investigates the impact of rotation speed on the natural frequency variations has been established. A Newmark method combined with Newton Raphson schema is target to compute the wind turbine response in the time domain, considering both linear and nonlinear analyses, while accounting for aerodynamic loads and a flapwise and an edgewise deflection curves were extracted. The findings indicate that the natural frequencies seem sensitive to the nonlinearity and the elevation of the wind velocity.

In many industries, there is a need to develop more lightweight materials for a wide range of load situations. The common process to achieve this is mainly the utilization of architectural sandwiches where two skins are printed on an architectural nucleus. Architectural nuclei are known for their structural diversity where each structure provides specific mechanical and dynamic properties that adapt to several industrial sectors. In this paper, tensile properties and failure mechanisms of a rectangular nucleus are studied. The rectangular nuclei are made from a bio-based material which is flax fibers-reinforced polylactic acid. A Raise3DPro2 Plus printer is used to fabricate the specimens. Several tensile tests are performed on the rectangular nuclei with different relative densities of the unit cell. The aim is to study the relative density effect of rectangular nuclei on the tensile properties and the damage characteristics of this material. Acoustic emission technology is applied to quantify the material failure mechanisms. The main results of this study show a very significant effect of nucleus density on the structural Young's modulus and Poisson's ratio. A numerical model is developed in this study. A good correlation is observed between the experimental results and the numerical predictions.

3D printing was triumphantly implemented for the fabrication of various architectural composites. The lightweight materials are developed for a variety of load situations across many sectors. The most popular method for accomplishing this is to use sandwiches with an architectural core. The cores are characterized by a diversity of structural forms, each of which has distinct mechanical characteristics. In this chapter, 3-point bending tests are undertaken with acoustic emission (AE) to investigate the mechanical behavior of 3D-printed short flax fiber-reinforced Polylactic acid. The specimens are built using the RAISE3D Pro2 Plus 3D printer. Mechanical experiments were then carried out to study the bending properties of the anti-trichirals structures. The analysis involved specimens with two distinct base cell radii, aiming to highlight the impact of the cylindrical node’s size on the sandwich’s bending strength. In addition, characterizations of the AE response are also examined. Non-destructive testing technology (NDT) by AE method is successfully employed to evaluate the 3D printed sandwich mechanical behavior and notably the bending deformation and damage. The results of cross-validation of cluster analysis, known (k-means) and principal component analysis (PCA) show that the AE settings, including duration, amplitude, rise time absolute energy and the number of counts to peak are associated with failure process of the specimens.

Nowadays, wind energy plays a crucial role as an alternate renewable source that affords in one hand the fossil fuel depletion and its highly soaring cost and to handle in the other hand the excessive demand of green power at cheapest price as possible as it can be. According to the Betz limit, we can only convert at least 59.3% of the kinetic energy into mechanical power. Consequently, several techniques have focused on maximizing this amount of transmitted energy especially the Maximum Power Point Tracking control (MPPT). This study presents a comparison between three types of MPPT control methods which both are artificial intelligent and another is a conventional control technique of a wind turbine using as generator a Permanent Magnet Synchronous Generators (PMSG). Indeed, an Optimal Torque (OT), an Adaptative Neuro Fuzzy Inference system (ANFIS) and Artificial Neural Network control (ANN) are the control techniques simulated and analyzed next in this paper using MATLAB-Simulink software.

This research assessment deals with the elaboration and the characterization of polyamide 6–6 (PA66)/copper (Cu) micro-composites. Four weight proportions of the Cu particles in the range of 0–15 wt% were considered. Composites were developed using an internal mixer with two blades to achieve the mechanical mixing. This first step is followed by an injection molding process. Scanning Electron Microscopy (SEM) and micro-tomography were utilized to qualitatively analyse the distribution of copper particles in the PA66 matrix. The visualizations revealed that the copper particles were spherically shaped and evenly distributed throughout the matrix. The study also used nano-indentation to quantify its measurements like indentation hardness and indentation elastic modulus of the different composites. It was demonstrated that both properties were enhanced by incorporating Cu particles. The friction characteristics of PA66 composites were compared to those of pure PA66. It was shown that copper powder improved considerably the friction and wear properties of the composites. Overall, the study's results offer insightful informations about the characteristics of copper-filled PA66 composites and their prospective uses in fields where minimal friction is sought.

The ability to change the surface properties of a component by the use of surface coatings has opened many new applications in a number of large technological areas. Over the past few years, surface coatings technology has been widely applied in various sectors, including electronics, automobiles, aviation, modes, and daily necessities. In this paper, the wear properties of the steel tool AISI P20 unheat-treated uncoated and coated by NiB were studied using friction tests. The pin-on-disc tests were completed under dry sliding conditions at different loads; 2N, 4N and 7N. Optical microscopy and laser profilometry were employed to analyze the wear track of both uncoated and NiB-coated AISI P20 steel. In both cases, AISI P20 steel exhibited abrasive wear as the predominant mechanism. However, it was observed that the extent of damage, as indicated by wear depth and width, was more pronounced when AISI P20 was uncoated. Consequently, the Ni-B coating demonstrated an enhancement in wear resistance and overall tribological performance for AISI P20 steel.

Printed circuit boards (PCBs) are essential modules which are incorporated in a wide range of industrial equipment in order to control or signal manipulation applications. Printed circuit boards are subjected to various types of loads, such as vibrations, shocks and static loads. This paper discusses the development and use of an analytical approach for predicting the dynamic response of a flexible printed circuit board (PCB) at an early stage of design. The main contribution of this research work is to reduce the designing time and to increase efficiency, computer simulation (modeling) commonly used. As an application, the dynamic response of a simply supported circuit board, during the drop test, to an impact load applied to its support contours is presented and discussed using the modeling software tool Modelica/Dymola. An overview of the desired system behavior can be performed and the effects of some parameters on the system response can be analyzed. The model can be helpful in the analysis and the design of PCB structures experiencing dynamic loading in the preliminary vibrational design. For validation purpose, the obtained results are compared with those reported in the literature.

The control of the mould sand and its characteristics is essential for optimal economic production and predicting casting defects. Properties of the sand, such as compression strength, compactibility, and permeability, are closely related to input parameters such as water and clay content, making the relationship between these parameters and casting properties complex. An industrial case study on the metal penetration defect was conducted to determine the optimal mold compactibility as a function of the severity of the defect. The results showed that high active clay content can result in severe metal penetration defects, and acceptable values for mold compactibility range between 36% and 40%. A diagram, thus, has been elaborated that defines the area of use of the foundry sand as well as the corrective actions in terms of input parameters (clay and water) which can help modern foundries control raw material input in order to obtain the desired characteristics.

In gear systems, current models mostly supposed gear mesh damping ratio was a constant. In real applications, gear mesh damping may not be constant for different tooth contact positions and is dependent on the gear damage. For that reason, the damage effect on mesh damping has been the subject of intensive research and may deserve some investigations. In order to determine whether or not damage contributes significantly to the mesh damping in a one-stage gear system, a general dynamic model is developed, and a numerical simulation is achieved. The continuous wavelet transform method (CWT) is used to provide dominant frequencies and damping ratios for each mode separately which are essential information to learn about the damage effect on mesh damping. Several types of gear defects can be found in the literature. In this paper, a gear eccentricity defect and tooth crack are introduced in the model to study their influence on mesh damping.

The present study aims at analyzing the free vibration behavior of hybrid fiber-reinforced laminated composites is a complex phenomenon that is influenced by a number of factors, including the type of fibers used, the volume fraction of the fibers, the stacking sequence of the plies, and the boundary conditions of the structure. This study investigates the free vibration behavior of hybrid fiber-reinforced laminated composites to obtain their nondimensional natural frequency. The materials used are a functionally graded ceramic/metal mixture (FGM) composite and a carbon nanotube reinforced composite (CNTRC) with a volume fraction of 0.11. The analysis is performed using the finite element method for a simply supported plate with a thickness of 0.1, consisting of n plies with NL sublayers each. A linear distribution (UD) is used for the CNT case, with a low power index (Pin) of zero. To validate the accuracy and reliability of the proposed models, the results of the nondimensional natural frequencies and mode shapes obtained in this study are compared to those of existing models in the literature using COMSOL software with different meshing sizes.

Loosening of an assembly is a critical phenomenon, it can cause damage in the aeronautical field which uses a huge number of bolted joints. It should be studied correctly to avoid catastrophic phenomena. Most of studies focused on the loosening phenomenon resulting from transversal load or axial load. This paper is dedicated to the study of the influence of vibration in the torsional direction on the loosening phenomenon. A finite element model is performed on an assembly subjected to vibration resulting from a shaker and exited at its second Eigen frequency. Two configurations will be studied to show the influence of the shaker position on the loosening phenomenon. A bracket is fixed on the shaker to transmit vibration to the assembly. The influence of the bracket length on the loosening phenomenon will be tested. A simplified model of the bolted joint is adopted for the simulation of the loosening to minimize and simplify the numerical problem.

Acoustic coatings are the most widely used techniques for attenuating sound levels in duct systems. Porous materials are preferred because their performance is less frequency dependent.One of the methods used to describe the acoustic propagation and scattering in ducts containing these porous coatings is the scattering matrix method. The scattering matrix allows to describe the acoustic properties of such a material. This matrix presents a powerful tool for the characterization of duct systems containing porous material because it presents important detailed information on the transmission, reflection, and attenuation phenomena at a duct element.Several works were aimed at calculating the scattering matrix. Others have dealt with some experimental means to measure it.In this paper, A comparison is made between the simulation of an experimental procedure for calculating the diffusion matrix and the transfer matrix method (TMM). Good agreement was found between experiment and theory.

Deep drawing is a popular manufacturing process across many industries as it has the ability to efficiently produce complex shapes with high accuracy and repeatability. However, deep drawing is limited by various factors such as the formability of the material being used, part design, and deep drawing process parameters. The shape of the punch can also affect the deep drawing process. Finite element analysis has become an essential tool, allowing manufacturers to improve their product quality while reducing the need for expensive experimentation. By using advanced simulation techniques, our objective is to gain a comprehensive understanding of how varying punch characteristics can influence the formability and the quality of the deep-drawn components. In this study, we numerically investigate, by simulating different scenarios, the effects of punch radius and shape on the formability of coated Aluminum sheet in deep drawing process. This work is important to optimize the deep drawing process, reduce defects, and improve the efficiency of deep drawing operations of coated Aluminum sheets.

The car gearbox is running under acyclism regime since it is excited by the variable load and speed generated by the Internal Combustion Engine (ICE). These excitations can be transmitted to the car driver through the gearbox. Most of the research works on its dynamic behavior considered a simple stage gearbox and four cylinders engine whereas the car gearbox is two stages of gears, and the three cylinders gasoline engine is frequently used. For this, the car gearbox was modelled to establish numerical motion equations using Lagrange method. Then, the load of the three cylinders gasoline engine is modelled as an external force. The gasoline engine speed at which the stiffness of the mesh is modelled with variable periods of time is a harmonic variable speed. Obtained results show that the external excitation of the ICE is more important than excitations due to contact conditions between gear teeth. Because of this, the acyclism frequency dominates the gear mesh frequency and we observe only the own frequency of acyclism in the spectrum of acceleration signal.

Wire and arc additive manufacturing (WAAM) was developed as an efficient technique based on the layer-by-layer build-up approach. WAAM presents a powerful production process offering low-cost manufacturing of complex components used in different industrial applications. Process parameters such as energy input generate a specific structure thermal history of the built structure and thus affect the resulting components properties. In this work, two 5356 aluminum alloy components were build-up by WAAM using different heat input and then machined along the horizontal and vertical directions. Tensile tests were used for the mechanical characterization. The results reveal that for the component manufactured with lower heat input, the mechanical properties (tensile strength and elongation) of vertical samples are lower than those of the horizontal ones. The tensile fracture analysis of the tested samples highlights structural defects namely a lack of cohesion at some regions, which may be one of the causes of anisotropic mechanical properties. The adopted strategy using higher heat input for 5356-Al enhance the resulting internal structure and consequently improve the mechanical properties.

The main objective of each company is to increase customer satisfaction by providing the product they need, in the required quantity and at the right time. In healthcare, the main goal is to satisfy the patients with the good quality of care and reduce the costs in the healthcare organizations. To achieve this objective, managers are invited to apply methods that contribute to the continuous improvement of service quality, such as the application of lean management activities (Value stream mapping, Six Sigma, 5S, PDCA, visual management, etc.…) which have proven effectiveness through several research works. The main purpose of this paper is to demonstrate the role of lean management system to improve patient satisfaction and reduce time wastage in healthcare. The case of a private Tunisian polyclinic is treated, where the ishikawa diagram is used for the diagnostic of the polyclinic situation and to highlight the existing problems, and a two Lean Management tools are applied: Visual Management and 5S Process.

As the demands and challenges of today's industries are continuously changing, for this reason, the industry is trying to revolutionize the way, and the technologies applied eventually. Optimizing the manufacturing process to achieve maximum production with minimum exploitation of resources is the main objective of Industry 4.0 by improving its performance indicators such as; flexibility, resilience, robustness, relevance, agility, responsiveness, and proactivity. The birth of I 4.0 is due to the development of new tools that have made this revolution tangible. Artificial Intelligence (AI), Internet of Things (IoT), Cloud Computing, Big Data, Augmented Reality, Cyber-Physical Systems (CPS), Vertical and Horizontal Integration, Cyber Security, Collaborative Robots, and Smart Machines or Machine Learning. These new technologies are the driving force behind technological advances, including the availability of large amounts of data that these technologies can exploit. However, adopting AI technologies for I4.0 varies considerably across industry sectors.