Current Methods of Construction Design

The article describes the optimization of the driver’s seat adjustment mechanism. Technical, functional and customer requirements for the seat were laid. The original seat was analyzed using: DFA analysis, complexity calculation, theoretical efficiency calculation, process flow diagram. An analysis of existing production technology and a rated optimization potential has been done. TRIZ analysis was performed. We looked for system elements that could be substituted by a supersystem and then replaced. The goal was to simplify the mechanism, to reduce the number of elements while preserving the function. Low-pressure casting and sheet forming technologies and welding were compared. Four optimization options have been developed using the FEM. The load data measured by the real crash test and provided by the manufacturer were used as input data. Innovated parts had to meet these load criteria. It is a condition of the innovated driver’s seat mechanism to show the same or better resistance to the existing mechanism in the case of a passenger car accident. Customer safety has to be preserved or improved. An economic assessment has been made. Based on this, the best optimization option was selected and presented. The economic return, the complexity of production, the most suitable technology, the potential for further optimization were taken into account.

The article deals with optimization methods, their basic properties and the division. Particular emphasis is placed on numerical methods that are suitable to optimize the problem with a large number of design variables and are relatively robust. The methodology by which a construction can be optimized by the automated process is also described. The process consists of linking commercial programs, namely Creo Parametric, ANSYS Workbench and MATLAB. The program Creo secures cad data; ANSYS Workbench serves to calculate FEM simulations; and MATLAB manages an optimization process based on inputs and outputs and creates the interface between programs and provides the flow of information. Also, the article describes how to create the link between these programs. Thanks to this connection, it is possible to automate the optimization process by creating a program in MATLAB environment and also to select and implement a suitable optimization algorithm according to the optimization task.

This article deals with the innovation and construction design of the cutting module, which is part of a modular production line for the production of sophisticated adhesive wound covers with respect to the Cleanroom ISO Class 8 standard and chlorine resistance. The start of the project is based on innovative methods. First, patent survey and market research were conducted. In addition, the identification and analysis of innovation opportunities were carried out, and finally, the innovation statement was formulated. The QFD method and the morphological matrix were chosen to generate the concepts. Subsequently, one of the concepts was selected using multi-criteria decision-making provided by the AHP tool. The chosen variant was further designed and processed, including strength calculations of important parts. Deformation stress tests were performed in finite element software. Integral part of this work is the technical documentation of the individual components from which the product can be realized.

This article deals with the design of positioning device used for easier montage of various parts, especially blowers and compressors. The working desk is part of the motion positioning device which rotates around horizontal axis of positioning device. Working desk is held in pair of bearings and mathematically solved as a refracted beam. Design of the device must be universal for many types of assemblies and cannot be fixed to the ground therefore, is obtained with two pairs of wheels to provide mobility. While assembling pressing machines bearing with electromotor are fit into the housing which is mounted to the positioning device, the device is in horizontal position toward floor and is able to absorb forces from pressing process to the positioning device. FEM analysis is used for stress examination of critical areas. When pressuring is started, positioning device must hold on a stationary position. FEM analysis is used to determine maximum radial ratio of blower fixed to the geometric center/centerline of the positioning device. Positioning device must stay stable in all operations, therefore was created chart of the maximum stable position around horizontal axis for 500 kg load from horizontal to the most critical vertical position turned by 90°.

The paper deals with the possibility of increasing the accuracy of measurement of float indicators (float gauge) for level verification in high-capacity oil and hydrocarbon fuel tanks. Verification of accuracy of float level gauge is required by law. The new device will use Renishaw’s metering system. The new measuring system will work with an accuracy of 10 times the current measurement system. The current measuring system uses an accurate sliding scale and the rope of the authenticated measuring system is pressed by point contact for manipulation. The new system utilizes the direct contact of the rope and the measuring wheel. The paper focuses on the overall concept of a measuring device. The paper also deals with the determination of the geometric tolerances produced by the device components to minimize the measurement error. This article was based on the solutions to common project of applied development Slovak Legal Metrology, Slovak University of Technology in Bratislava, University of Žilina, with the support of the Agency for Research and Development.

The torsional vibrations generated by combustion engines installed in vehicles have an undesirable effect on the life and reliability of individual components. Vibration and excited noise reduce the comfort of the operator and crew. The subject of torsional vibration reduction is therefore highly current. One of the options for reducing torsional vibrations is the current use of dual mass flywheels that are included between the combustion engine and the vehicle’s gearbox. An alternative solution to the reduction of torsional vibration is the use of a pneumatic dual mass flywheel. The pneumatic dual mass flywheel is characterized by the fact that it is possible to change its properties during the drive operation. For the purpose of investigating the use of dual mass flywheel in combustion engines, it was necessary to create experimental devices and methodology to identify their properties. The experimental device is possible to identify the operational, strength and expansion properties of pneumatic dual mass flywheels.

This work is focused on innovation of the method of application of nanofibers on yarn. A candle filter is produced from this fiber body. The goal is to increase the productivity of nanofiber deposition and to remove unwanted effects on existing device. The procedure is based on innovative methods of product innovation. At the beginning of the work, a patent survey is carried out and the QFD matrix is compiled. Several concepts are proposed by morphological matrix and the analytic hierarchy process is used for selection of concept for designing. The selected concept is designed to meet the target parameters. An experiment was performed to verify the balloon parameters and the proposed concept is divided into three sections. The designed concept is compared at the end of the thesis with the current solution. A microscope with a magnification of one hundred is used to compare the nanofibres layer applied on a yarn.

The paper presents recently built experimental rig for testing of rolling element bearings. Test rig comprises patented support of tested bearing that enables simulation of wide spectrum of operating conditions including external dynamic load. Forced recirculation lubrication system can maintain the temperature of oil in the bath and control the flow of supplied lubricant by a membrane pump. Sensors attached to the tested bearing provide information about inner and outer ring temperature and vibration signal. The device is additionally equipped by bearing monitoring system based on induced surface acoustic wave transmission characteristics that are sensitive to lubrication state and will be subject of prepared research. The chapter starts with a system-level overview that allows reader to get familiar with device before a detailed description of key components such as tested bearing housing, loading mechanism or control system. The experience obtained during the assembly and initial launch of rig in the form of lesson learned closes the paper.

The article deals with the reverse engineering procedure of the differential gear case from the racing BMW M6 for the GT3 series. The article contains a procedure for repairing a gear case with damaged functional surfaces after a bearing failure. During the drive, the bearing cage has probably been destroyed, causing the rolling elements to loosen and spill into the gearbox. The first part of the article deals with the creation of 3D data of damaged case and functional areas using 3D scanning by a portable handy scanner. The second part describes how to create CAD data for the machining of these surfaces and a description of the software used. In the end, accuracy checks are shown by comparing the generated CAD data with data obtained from 3D scanning. The article also outlines the repair procedure by re-welding the damaged surfaces and obtaining the zero areas needed for subsequent CNC machining.

The paper is focused on the minimization of vibration transmitted from electric golf cartwheels to seat and seated person. This vibration appears during golf cart driving on uneven terrain of the golf court. The paper also focuses on improving the driving comfort of transported persons on an electric golf cart. This problem can be solved according to (Svoboda et al. in Bag Development s.r.o. Golfový vozík s bateriovým elektrickým pohonem a sedákem [1]) using the elastic and damping link between cart frame and seat tightly connected to battery of electric power. The designed solution of an additional vibration isolation device comes from measurement in real conditions of kinematic values of the vibration on seat and from experimental laboratory measurement of dynamic parameters of the system. Based on acquired data, the mathematical model of the system was made and dynamic parameters were optimized. This mathematical model of designed solution describes golf cart as system of masses connected with elastic and damping links. The result of mathematical description of designed solution is the reference step response of golf cart seat.

A harmonic drive gear is, in fact, a differential gear with front-wheel drive in which the gear is achieved by elastic deformation of the flexible spline. The spline harmonic drive gear is typical for its unique structure called “strain cam wave generator”. The principle of functioning of these gear systems is based on the mechanism of rotationally elliptical deformation of the flexible spline using the elliptical wave generator and subsequent tooth generating. When dealing with these types of gear systems, we come across the term “backslash”, which is a surplus clearance between the generating teeth. When designing a harmonic drive gear for robots, it is important that the backslash is as low as possible. This chapter focuses on the preparation of the finite element model of a harmonic drive gear. It provides readers with a complete overview of the functions of these special, really precise and stiff gear systems and their properties. Harmonic drive gearing systems have been widely used in the area of precise control. Precise reduction and positioning have been mainly used in robotics. Its high rate of precision and weight has been used in the aviation industry. The system is also used in the engineering industry for transmission of high torque, conveyor and turbine drives and in many other machine applications.

Current innovation and mechanical engineering use, among other things, so-called trends of evolution of engineering systems (TESE). They describe natural transitions of the engineering system from one state to another and are generally valid for all engineering disciplines. In the area of flood protection systems innovation, one of the most significant trends is the trend of increasing dynamicity. This trend lies in the fact that during the development of the engineering system (components), the flexibility, dynamism, or adaptability increase. The development of engineering systems in the direction of this trend proceeds from an initial rigid structure with unchanging parameters to a more flexible and variable structure with more degrees of freedom, with adjustable parameters and a working mode adapted to changes in the external environment. The article deals with the fulfillment of this trend in the field of flood protection systems or flood barriers and presents examples from patent documents.

The article describes the temperature oscillation caused by shock mechanical parameters changing. The special effort on the heating curve parameters is put. The shock changes of the mechanical parameters (change of floating power) cause the extremely fast temperatures changes ongoing on the teeth flanks. The gear oil can be damaged during these processes. The lubrication parameters are changing and mechanical failures can be caused too. The automobile MQ100 gearbox for the measurements was used. The unique equipment for the temperature measurement was applied. The special stand for the operation of the gearbox was used. The gearbox operation condition was similar as in passenger car operation, without other heat sources (as a combustion engine) only. This short article describes the automobile gearbox final drive pinion teeth temperature measurements during the shock power float parameters changing. The aim of the article is a description of the tooth heating curve parameters. The goal is the maximal temperature gradient computing.

This article deals with the design of the equipment for bearing stiffness determination of the shaft. The other part of the thesis is concerned with an experiment of the equipment. The knowledge of the bearing stiffness is important for finite element analysis (FEA) to help determine the correct type and size of the gear modification in the car gearbox. At present, this stiffness is not included in FEA software. The stiffness of the bearings is investigated statically and dynamically with rotational shaft. This is one of the requirements on the device. The first part of the article is focused on the design of the device for the bearing stiffness determination. The second part elaborates on the measurement methodology and the evaluation of the result from the measurements. The result of the measurement is not the rigidity of the bearings, but the displacement of the shafts and the tilting of the inner ring. In order to determine the bearing stiffness of these results, it is necessary to know the theoretical displacement of the shaft point in which it is measured. Shaft bearings are replaced with ideal joints. This substitution is done in FEM calculation of the shaft. The final stiffness is determined from the measured data.

For loading capacity calculation of gears, a number of standards are used. In our country, the use of the standard ČSN 01 4686 is slowly coming to an end. Unfortunately, this standard does not cover the currently designed gears with non-standard profile. Consequently, designers go to other standards—DIN 3990 or ISO 6336. ISO 6336 was essentially taken as a replacement for the ending standard ČSN 01 4686. This paper deals with this standard, specifically with its second part. “Calculation of surface durability (pitting)” is the title of the second part of ISO 6336—“Calculation of load capacity of spur and helical gears”. The standard was issued in 2006. This issue is still valid, supplemented in 2008 by Technical Corrigendum 1. It is a basic standard and at the same time a guideline for a very important calculation of the contact stress on the flanks of the teeth of gears. This article points to some details in the standard. It also shows an overview of typing errors in this part of the standard. It also states their correct wording.

The article deals with the issue of real tooth contact on the helical gearing in the car gearbox. Theoretical images of the tooth contact in the available literature do not show all information about tooth contact looks and how are spreads on the real tooth flank surface. This article shows in the detail, how looks the contact line and the footprint (contact pattern) caused during tooth meshing on the real gearing in the car gearbox. It also shows, where the contact of the tooth begins and in what direction is expands on the tooth flank. This all is created for the comparing on different levels of load, because on the tooth are created micro-geometry modifications, which causes little bit different shapes of footprints than on unmodified gearing. These real footprints represent a better imagination for understanding how tooth meshing of helical gearing looks and how is changing the size of footprints due to increasing loading.

This article is based on rules used in ISO GPS standards. During few last years are applied to drawing documentation environment various modifiers, specifications, and symbols from 3D annotated model. There CAD model describes nominal shape of the part. Specifications are then defined by annotations directly in the 3D model [1, 2]. Specifications from 3D annotations are applied in 2D drawing documentation now. The significance of these specifications (modifiers) from field of geometric tolerance is same in 2D and in 3D documentation. This is the reason why it is necessary to know, recognize and applied these specifications. The basis for these specifications is the latest edition of the standard ISO 1101 from 2017. Main new specifications are: intersection plane indicator; orientation plane indicator; direction feature indicator; collection plane indicator. With these specifications, disappeared dependence of placement of geometric tolerances on specific 2D view in orthographic projection (ISO E). The method of evaluation for metrology was also better specified. Used these specifications, we can better and more clearly positioned geometric tolerances on a 2D drawing or also into a parametric 3D CAD model using PMI dimensions. This article explains application of these new symbols to specific components with detailed descriptions. Apart from symbols for geometrical tolerances, are also very important symbols for datum, which are defined in ISO 5459. Furthermore, the issue of linear and angular dimensions from standards ISO 14405-1 and ISO 14405-3.

The article deals with the creation of 3D model of slewing bearing with the support of the 3D modeling software Creo Parametric 3.0 and with support of Apex Grizzly 16, that is especially suited for creation of a high-quality mesh on a variety of 2D or 3D models. The basic task will be, to define specific type of slewing bearing and find out the basic parameters, like ball diameter, diameter of inner and outer race, and pitch diameter of rolling tracks that are necessary for its construction. After we create suitable 3D model of slewing bearing, we need to divide the base model of ball into the several parts that will allow us to create a quality and uniform finite element mesh on the entire volume of the meshed part. After transforming the model into the program Apex Grizzly, we can create basic mesh and find optimal mesh values for each element of divided bearing separately.

This article deals with the design optimization of the micro-hydropower plant. This mini-power source is designed as an additional power source for small recreational objects or remote places with access to a water stream of flow rate approximately 0.4 m3/s. A paddle wheel with 3 m diameter is welded from sheet metal. The paddle wheel is designed for a rotational speed of 5 rpm. The electric generator with planetary gear is integrated into central supported tube. The original construction was very robust and heavy. Particularly due to the high weight, it was required optimizing of design. A finite element model of the whole structure of the hydropower plant was created. Mechanical stresses and deformations in main part have been analyzed. Based on these analyzes, optimization has been proposed with the result of weight reduction while maintaining of use properties and with good durability.

In contribution are compare two standards for testing the roll-over protective structures (ROPS) frame. The ROPS can be tested by different standards. Mostly used standard is the European Union (EU) regulation for protective frames of agricultural and forestry machines No. 1322/2014 for ROPS “Tractor” or ČSN EN ISO 3471:2008 Earth-moving machinery-laboratory tests and performance requirements for roll-over protective structures. The aim of the study was to investigate the protective structure of the cab of a truck MERCEDES 4 × 4, to cater for both European standards. Furthermore, the calculations were compared with Australian standard AS 2294.2-1997 Earth-moving machinery-protective structures. Also the laboratory tests and performance requirements for roll-over protective structures was made. Suggest a change ROPS a proposal to verify calculations deformation, stress, and energy loss when objects falling on the car cabin. The car is built into mining operations and large excavators an object may fall on a passing truck. Based on the calculations, the design of the cabin protection equipment was optimized by different standards.

This paper approaches the design, modeling, and manufacturing process of the multipurpose steering wheel for a formula-style race car. The Multipurpose steering wheel is a device for lateral control of the formula student and also for changing the formula’s parameters. Steering wheel’s parts are designed with an aim to comfort, usefulness, manufacturability, and cost of prototype. Subsequently, the main body modular mold design and manufacturing process is presented, taken into the account the technology of production and material with suitable attributes selection. For the steering wheel, it is utilized the technology of pre-impregnated carbon fiber fabric reinforced polymer (CFRP) cured in an autoclave. Design of layers of composite material is described in the detail, followed by the material’s bend test. Custom internal parts made by 3D printing technology with a purpose of mounting electrical components and mechanical control components are demonstrated. The final product is part of formula student electric racing car SGT-FE18.

This article is focused to design of vacuum chamber for deep drawing machine working by high temperatures. The high temperatures are demanding because of use of molybdenum sheet, which should be drawn by temperatures approx. 300 °C. The thermal analysis is important for the correct design of the deep drawing machine for two reasons: The first is the correct temperature of the molded material—molybdenum sheet and the second is the temperature around the seals of vacuum chamber. The simulation forms the basis for selecting the appropriate type of seals. The result of the simulation is a thermal field of working components: the punch, the die, the blank holder, the working plate, and the working table. The second important analysis result is the temperatures of components, which are in contact with seals in particular places.

The very important current trend in machinery is the reduction of vibration and noise, mainly in terms of human health and lifetime and safety of machines. Our current research is focused on continuous tuning of torsional oscillating mechanical systems during their operation, mainly in terms of torsional vibration magnitude, using pneumatic flexible shaft couplings (pneumatic tuners) and electronic control systems. Our electronic control systems work with the manipulated variable—gaseous media pressure in pneumatic couplings and with controlled variables, which can be, for example, the magnitude of torsional or rectilinear vibration, the noise level of a mechanical system, etc. In our case, the twist angle of a pneumatic coupling is very important variable, which can be directly the controlled variable, or it can be used for the computation of controlled variable, for example, for the computation of the load torque transmitted by the pneumatic coupling. Therefore, the objective of this paper is to present a contactless device for the measurement of the twist angle of a flexible shaft coupling. The device was newly developed by us and uses a pair of optoelectronic sensors and real-time data processing.

To determine the size of the cam mechanism is an important task of the cam designer to produce the contour of the cam with high precision. There are two major factors which affect cam size, the pressure angle and the radius of curvature. Both of these involve either the base circle radius on the cam Rb when using flat-faced follower, or the prime circle radius on the cam Rp when using roller or curved followers. Therefore, the paper presents the relations between the geometric parameters and the cam angles of the groove cam mechanism are established. To calculate each contact point at any instant moment by using the method according to velocity and geometric relationship of instant velocity centers. Hence the cam profile was defined by contouring of the contact points. Moreover, a design example of constant-diameter groove cam is illustrated in this article.

The article is directly linked to the article called “Geometric Specification of Complex Spatially—Oriented and Compliant Components I”. Manufacturers of complicated and flexible machine parts, particularly in the automotive industry, are finding themselves in almost insoluble problems when designing TS and preparing their technical documentation. These problems arise mainly in describing the geometrical properties of technical products in order to ensure their errorless production and control in sub-suppliers. Unfortunately, GPS standards are not flexible enough to meet these specific requirements, and from this reason manufacturers or their consortiums respond to this situation by defining their own procedures and regulations that allow them to solve these problems. However, the negative consequence of this state is that there is no general agreement and consistency in the description between the individual internal rules of the firms and this creates considerable problems for the subcontractors, who cannot properly read the technical documentation and correctly set up production and control procedures, which can lead in some cases to fatal consequences. The aim of this paper is to identify these inconsistencies and propose ways to solve the above-mentioned problems.

The purpose of this contribution is to invent new spring, which will be made of carbon woven material. In this case, we examine spring properties in FEM software intended for testing of composite materials. This research is based on the need of special lightweight spring, which will have long length of compression and excellent resilience. Design of this unconventional spring we want to use as spring with damper in our project for extremely terrain lightweight vehicle. We designed two types of springs. First is made of corrugated carbon strip aligned into square and second is helical conical compression spring of rectangular wire. These springs were tested for the maximum load of 2000 N and we monitored the stress and deformation. Both springs were also tested with different angle direction of forming layers. The article wants to find new field of usage of carbon material through good elastic properties in spring sphere.

This contribution describes the impact of the spin cycle of a washing machine on its acoustic power level and examines the adverse effects occurring during the spinning. Such effects result in an increase in the rated acoustic power level shown on the rating plate of a particular major appliance type. To enable an objective assessment of this problem, a series of measurements is required since many of those effects are accidental and occur sporadically. The rating declaration for a particular type of washing machine is based on three repeated measurements made on three sample units. The measured values are then used in the final calculation according to the relevant standard, in a manner that allows the repeatability of measurement. The wash cycle ends with the final water discharge, which is followed by a series of spin phases at different speeds and varied drum imbalances. The test code for the determination of airborne acoustic noise foresees the specification of a 50-second interval of the acoustic power maximum profile for use in the declaration calculation. If the measured acoustic power levels differ between the repeated measurements, it can reasonably be supposed that an unwanted effect is present that needs to be identified and eliminated to avoid a further increase in the total acoustic power level of the washing machine during the spin cycle.

The deep core drilling has currently wide application—construction drills, geological exploration, drills for measuring pendulums in dams, etc. It is very important and useful to know the drilling process parameters precisely. The most important is the used torque, pressure and rotation speed of the drilling machine necessary for the optimal drilling process. These parameters depend on the strength of the drilled material, for example, rock, sand, clay, etc. and of course on the drilled diameter and applied pressure. In-time identification of the drilling parameters enables the optimization of the drilling process directly during the performance. Furthermore, it can serve for the real data acquisition, which could be used for later drilling planning in similar geological environment. Obtained data are also very useful for designing new drilling machines. They could be designed according to their future usage to the optimal performance. This contribution deals with the design of the new sensor for in-time identification of above-mentioned core drilling parameters. The sensor is based on the strain gauge measurement and enables online monitoring of the drilling process. The measured data are also stored and could be post-processed in longer time context to obtain also the drilling capacity of the drilled material.

One of the biggest barriers to the development of electromobility is the fear of people, because electric car has a significantly shorter range than conventional car. In modern electric cars to reduce electricity consumption and the range, complex technologies are used as energy assist. The intelligent energy assist role is to optimize the way of driving to minimize energy consumption by means of video and audio communications with the driver. The energy assist is not only predicting the range calculated from the difference between the received and consumed energy. Energy assist controls, manages, updates, and communicates with the electric car driver. It even foresees a compromised run to the nearest charger, so the driver warns and proposes austerity measures. Energy assist performs the tasks before driving, and then throughout the drive to the charging station. The aim of our research and development is the energy assist of the electric car driver. Modern components in the Edison electric car, built at the Department of Design and Mechanical Elements, enable the collection of a wide range of data, allow for changing set parameters, monitor their impact on energy consumption and measurements on the roller dynamometer, and verify the change of parameters on the road in various driving and climatic conditions.

The article deals with the contact analysis of selected toothed gears of the two-stage front gearbox. They are extensively used throughout the machine industry, but also in other mechanical devices where input parameters change to the required working values. The aim of this work is to point out the effect of deformations of the individual gear components on the correctness of the toothed engagement. The work deals with the contact analysis of selected gears of the two-stage front gearbox. The subject of the study is to determine the resulting coefficient of unevenness of the tooth load over the width of the contact for deformation of individual parts of the gearbox using the KISSsoft computerized software. The pc software KISSsoft has several ways to define a coefficient KHβ. The method using the ISO 6336 standard was used in this case. Due to load, the teeth of the wheels resiliently deform. This deformation has an effect in an enlargement of the coefficient of the toothed contact. The result is the processing of data and their evaluation for individual types of deformations of the parts of the gearbox unit and the subsequent evaluation of the overall impact on the life of the gearbox.

The article deals with the diagram of the disposition of components and the creation of kinematic bonds of the test benches for transmission systems. The source of the drive on test benches is an electric motor. The article describes the configuration of components and the creation of kinematic bonds for the test bench with an open flow of mechanical power. The test bench also includes a dynamometer in addition to the electric motor. The article is also described an assembly procedure and creation kinematic bonds for test bench with a closed flow of mechanical power. In this, test bench used only an electric motor without a dynamometer. The electric motor is the same for both test benches. The kinematics of test benches is modeled and calculated in the Swiss program KissSys/KissSoft. As a result, the article deals with evaluation the energy balance of the individual test benches, especially by evaluation the energy balance of the electric motor.

The aim of this work is to determine the system of equations of motion for laboratory vibrating sorter mechanism. Description of motion and experimental verification is useful for designing of industrial vibrating sorters. These sorters are mostly used for sorting oil seeds in oil pressing industry. The mechanism which is described in this work is part of a laboratory testing circuit, where the methodology of designing of industrial machines is being developed. In this case, the sorter is placed on linear compression springs for easier dynamic modeling. The model of vibrating sorter is considered as a nonlinear two bodies system with 6 degrees of freedom and its solution leads to application of numerical solver using software MATLAB. In the second part of this work, the experimental measurement using optical methods is described. There are placed markers to be captured with the camera. With the help of software MATLAB and its image processing toolbox, the displacement of markers is determined and the correctness of dynamic analysis can be verified.

This paper deals with the numerical and experimental modeling of a cornea applanation during pressure loading–air puff. The determination of cornea applanation plays a key role in measuring inner eye pressure. A raised level of inner eye pressure is one of the most obvious symptoms of glaucoma. The numerical model for the cornea was established in consideration of its geometrical and physical properties using the finite element method. The primary applanation pressure was determined from obtained numerical results. The experimental model of the cornea was built from silicone. The experimental cornea was subjected to inner pressure that was measured by traditional medical contact and non-contact tonometers applied outside the cornea. Subsequently, the results for this model were used as the referential ones.

This contribution describes analytical evaluation and experimental verification of the friction and force conditions in the pre-stressed bolted connections. In the case of using standard fasteners (bolts and nuts), there were evaluated mainly influence of advanced coatings using and lubricants and modern insurance sealants and adhesives into the threaded surfaces of bolted joints. To achieve the set goals, modular design-testing stand was designed. Achieved analytical findings and experimental verification will allow to refine the technological processes of assembly of bolted joints, which will have a major impact on the strength, durability, and reliability of the screw connections (fasteners). Discovered knowledge is not currently available for design engineers during the designing of bolted joints. Design engineers typically use only recommendation of retailers and manufacturers when designing of bolted joints. In industrial practice, it is now very often required to calculate the screws according to the standard VDI 2230. Standard VDI 2230 specifies a procedure for the strength calculation of pre-stressed screw connections. The calculation is usually done on a personal computer using the KissSoft program.

The paper presents simple methods for measuring mass moment of inertia of rotors without need of dismantling the rotor or any special laboratory equipment. Only simple mechanical components (hub, threaded rod, weights, screws, nuts, etc.) and a common compact digital camera capable of taking 30 fps VGA video recording were used. First method is based on unwinding a specific mass (weight) hanged on string which is wound on cylindrical hub, where the times of consecutive rotations of the shaft are recorded. The second one is based on oscillation of pendulum with specified properties added to the rotor. In this case, the times of extreme positions of the pendulum are recorded. The evaluation of recorded time values is based on simple physical principles. The influence of various parameters as weight of added mass, length of pendulum and friction is examined. These methods are suitable for determining mass moment for machines without relevant technical data, when dismounting of rotor would not be an appropriate solution or special equipment is not available.

The paper deals with the life of the joints in the long-term operational load. For designing and dimensioning is important the feedback that the design was correctly designed and the component was not over-sized or undersized. This feedback becomes increasingly important, because it is now a trend to design lightweight structures with maximum use of the material. The consequence of this suggestion method is that the established safety margin does not allow for any errors or inaccuracies. The danger and weak side of this approach is to estimate the long-term life of the designed structure. In the research, we had the opportunity to analyze riveted bridge structure, which has been in operation since 1905. An analysis of the residual stress is published in the paper and is compared with the assumed bias in the newly made construction. The state of the rivet joint after a century operation is judged on the basis of this comparison.

Requirements related to accuracy of measurement and other metrological properties are required for measurement. Expression of the quality of the measurement is generally solved by the uncertainty of measurement. For measurements in industry, in addition to uncertainty increasingly also used capability index. We take advantage of experiences when determining the capability of production processes. There are some specifics related to the probability of their validity and in particular due to the uncertainty of the check measurement standard used. With help of this standard, we determine capability of measurement process. This contribution is addressed mainly to the impact of the uncertainty of a check standard for the capability index calculation. In practice, it is generally assumed that the uncertainty of the check standard in the assessment of the capability indices of measurement process is negligible. However, there may be cases that it is not negligible. In this paper, we examine how uncertainty of the check standard affects capability indices. This may be particularly important for lower index values, when data from the uncertainty of the check standard indicate that the process is satisfactory and in fact it may not be. The contribution also includes correction factors that allow correct the empirical value of the capability index and thus avoiding a possible mistaken assessment of the measurement process capability.

This paper approaches the creation of a digital twin based on a real measuring process in order to convert it into digital form as a virtual model within a selected software-based virtualization environment. Subsequently, a real-world data comparative flow is obtained from sensors; afterward, analysis within their calculated uncertainties and the digital twin data values are made. Such treated real measuring process data are inserted into a database, from where they are compared with the virtual digital twin data, where necessary trending-based analysis is made, for the purpose of proactive maintenance and the measuring process optimization. Such collected data are also stored for later-planned analysis within the Industry 4.0 concept in the form of big data databases.

Clinching represents one of the modern technologies applied in industrial production for connecting sheet-metal components into complex assemblies considering desired functionality and parameters. This article describes the use of FE method for simulation of connection of two sheet-metal plates using three clinching joints. The simulation model uses 3D solid bodies of connected sheet-metal plates and 3D model of the clinched joint. The clinched joint is modeled as a shaped interlock of sheet-metal plates with help of the tie connection and hard contact with penalty friction. The uniaxial stress in the vicinity of each clinched joints is used for analysis of the simulation results. This specific place corresponds with the placement of strain gauges during the experimental measurements on real specimens. The set of five simulation model and tested specimens with different joints spacing was used. Therefore, the results of simulation and experimental testing can be compared and used for general simplified analysis of load distribution between three joints depending on their spacing.

The comfort of seating on car seats depends on many parameters. People differ in sex, body, weight, quantity and quality of muscle tissue, and mental and nerve constitution. Such differences may, according to the actual situation, be a real mood, a sense of hunger or superstitions, levels of fatigue. In the list of differences we could continue, e.g. such as a people’s age, weight, corpulence, and so health, everything has a great effect on the comfort of sitting. Each individual person is different, behaves differently in the car, and feels different on the car seats while driving. Such an original person will sit on a unique car seat and demand it to suit everyone without distinction. We all understand that this is not possible. Without the personalization of the car seat we can not get anywhere. For the design of the right car seat, we will first have to carefully examine the person. Then we can ask the car seat to adapt to the person who sits on it, preferably automatically. Next we should explore, what kind of sitting more harms health of human, static sitting, or influence of mechanical vibrations (mechanical shacking) on human, or so damage to the human nervous system under the influence of driving (stress from complicated traffic, fast driving, etc.) A sitting position for a person is not entirely natural. Lying is definitely a better position, which is not good for the long term, but probably not in the car is good enough. So we have to stay at the seating. We will examine all the possible parameters and we may come up with some objective conclusions about the innovation of car seats.

The idea of technical safety system had been characterised. Presented were basic models of technical safety systems regarded to the highest measures of safety. Chosen measures of safety were included. Safety measures were illustrated with Kolmogorov equations. A safety analysis based on the engine room technical system with renewable elements was presented. It was illustrated, among others, with Kolmogorov equations. Measures of readiness and unreadiness as well as other measures of unreliability were indexed. In the complicated system, such as the engine room, its service depends on its accident-free functioning, as well and often on the safety of the environment. In estimating of the reliability of the technical system, it is necessary to take into consideration not only the system’s technical damages, but also the possibility of errors made by the technical personnel of the engine room. These errors cause various consequences of safety unreliability in the engine room system, and identifying these errors should be taken into consideration in the safety models and indicators of safety reliability and usable. Presented models do not include all of the possible areas. The presented way includes a narrow possible portion of safety analysis of exploitation in engine room.

The subject of paper is the design of control system of slow running bearings including strength analysis and load capacity measurement with the intention to apply the results to the manufacturing operation by the chain conveyor in the paint shop. The diagnostics of low-speed bearings is very desirable in a wide range of industrial sectors. Mainly, in the transport technologies is necessary to identify the damaged bearing before a production failure and large economic losses become. Chain conveyors are used in the bodywork painting process and chain wheels are mounted on shaft, which is currently mounted on two roller bearings. Shaft speed is relatively slow, ones of rpm. There is no doubt that the reliability of this construction has a main influence to the volume of production, especially since the paint shop is the bottleneck of whole production process of cars. The diagnostics of high-speed bearings is based on vibration measurement that is reliably used for many years (Sturm and Förster in Einführung in die Theorie der Technischen Diagnostik. Vieweg+Teubner Verlag, Wiesbaden, pp. 18–92, 1990 [1]; Hauptmann in Sensoren—Prinzipien und Anwendungen. Verlag C. Hanser, München, Wien, 1991 [2]). For the diagnostics of low-speed bearings, there is no appropriate physical method, which has been able to identify the bearing damage.

A method of calculating strength of frames of truck trailers with a central axle (axles) by using interface of MSC Adams software, for a dynamic analysis of mechanical systems, and NX Nastran/Femap software, for the finite element method (FEM) analysis, is presented in the paper. The transfer of information between these both programs is realized within this interface which is presented in detail in the paper. In the approach proposed, a method of reduction of degrees of freedom of the FEM model has been developed based on Craig-Bampton Method belonging to the group of methods known as component mode synthesis. At the beginning of the proceeding geometrical models of components of the truck and the trailer by using program SolidWorks have been worked out. In the analysis, it has been assumed that the modeled truck-trailer combination can drive over the road with unevenness of a specific shape. Some computing results were verified experimentally. The model of truck-trailer combination can be treated as its virtual prototype useful in a design process.

Calculation of the time course and speed of the oscillation motion dampened by centripetal force typically represented by sliding friction is rather complicated mathematical task, which is unnecessary to solve repeatedly for individual stages of the given oscillations until they are completely subdued. Using classical mathematics is a rather lengthy calculation when the results obtained for one of the examined oscillations are simultaneously the initial conditions for the following oscillations. The fact that said damping friction force changes its direction of action depending on the direction of movement of the mechanism considerably complicates given solution. It is rather complicated to solve the given calculation by classical programming in the available mathematical software. To solve the motion equation of such a mechanism, the mathematical software MAPLE using the signum function is being used. The values obtained by calculation are further verified on a model of low-energy device for the transfer of objects in a material flow designed on the principle of Karakuri mechanism.

The development of automatic washing machines and their gradual upgrade of already sold models is a very challenging task, mainly due to the changing operating conditions of the washing and subsequent spinning cycle. Increasing demands of consumers to buy the appliance constantly force manufacturers to continually innovate and improve their products to be able to succeed in the enormous competition. The trend for the centrifuging cycle lies in continual spin increase, resulting in greater forces and thus load on the overall machine construction. In general, it is known that with increasing spins more water is removed from the laundry. This is a significant benefit for the consumer as the drying time of the laundry is considerably shortened. However, the increase in spins can also bring the negative phenomena. One of them is a louder noise of the washing machine. Therefore, it is necessary to continually improve the procedures that can reduce the noise. For their correct design, experiments have been carried out. They have consisted of the measurement of the declaration, technical and subsequent measurement using an acoustic camera. Its using will determine the proportion of acoustic energy spread from individual construction components. These measurements and simulations will be used to set engineer theories so that it can be possible to transform the appliance, resulting in an effective reduction of the acoustic performance level. The theories will be verified by subsequent stated measurements and compared with the original values.

The specificity of ship power plants is connected with the vessel’s working mode and, above all, with operational safety. The synchronous generator powered by a combustion engine (diesel generator) is widely used in shipbuilding. During maneuvers and on “difficult” waters regions (sailing down the river, canal, straits, lakes, etc.), in order to ensure continuity of power supply, the parallel operation of generating sets is required. Safety reasons during maneuvers have impact on the parallel operation, rather than power demand. Therefore, auxiliary engines are often underloaded. These conditions cause that the fuel is not fully burned. It has an effect on operational problems of auxiliary engines and an increase in emissions of air pollutants. The article presents empirical researches of loads in ship generating sets in operational conditions requiring the parallel operation of sets for different types of ships. Moreover, it shows solutions that enable the limitation of unfavorable phenomenon of underloading of auxiliary engines so-called wet stacking.

Cardan shafts are commonly used when the drive and driven shafts are not coaxial but are still parallel. If the distance between the shaft changes, then the length compensation is moved under the influence of torque, and the resultant friction causes an axial force to be generated between the tooth flanks in the spline. This movement can be caused by the deformation of the frame or misalignment of shafts. The magnitude of this axial force is important for the design of other machine parts in terms of service life. This article deals with the measurement of torque and axial force on cardan shaft located on machine drive. This was done to verify the magnitude of the axial forces and torque at the run of the machine due to the fatigue fracture of the bolts at the cardan flange. Article describes the methodology of measurement, used equipment, and evaluation method. Measured values of the axial force are compared with theoretical calculations of axial force according to the manufacture of cardan shaft.

The article deals with the analysis of design solutions used in the implementation of vertical gardens. Besides the typological elaboration of the realized design solutions, the authors also deal with the assessment of typical concepts using the multi-criteria decision-making method analytic hierarchy process (AHP) that helps decision-makers and engineers solve a complex problem with multiple conflicting and subjective criteria. Initially, three typical vertical garden designs are isolated from existing solutions available on the market, which are then subjected to AHP. Within the AHP, the following criteria were chosen: modularity, capacity, comfort, and design. In the analysis, the complex unstructured situation of the individual components, the arrangement of the components in the hierarchical order, the allocation of the numerical value to the subjective evaluation of the relative importance for each chosen variable, and the evaluation of the highest priority were evaluated using the synthesis itself.

The subject of the paper is to examine the modal characteristics of the conveyor gearbox. On gearbox were detected excessive vibrations during operation. Due to the fact that the gearbox operates in continuous operation, it was an unacceptable condition. For this reason, experimental measurements were made using the bump test to identify the cause of excessive vibrations. In addition, a finite element analysis was solved in the ANSYS Workbench software to compare results with experimental analysis results. Load was considered from torque on the input shaft, the mass, and inertia effects of the electric motor and prestressed bolt connections. This means, we solved modal analysis of prestressed system. This approach has enabled us to better understand the dynamic behavior of the gearbox under real operating loads. Output from the finite element analysis also confirmed the oscillation tendency occurs mainly on the input gear shaft at certain natural frequencies. From analyzes results, we can conclude that resonance is caused by the matching of gear mesh frequency of the input gear shaft with one of the natural frequencies of gearbox housing.

The area of sealed flange connections of pressure vessels often encounters critical operating states that are defined by particular load conditions. These loads are exhibited from assembly stage, through pressure testing, to operation of the pressure vessel. The issues arising in assembly conditions alone are complex and significant. However, this article discusses the problematics of flange joints in subsequent conditions. Specifically, it is examining the effect of temperature on the bolt pretension. Stiffness calculations for machine parts which are constantly exposed to high temperatures at continuous exertion of force pose a significant level of complexity even nowadays. For calculations of pre-stressed bolt connections, the computations are even more complicated. This is given by the fact these are highly complex components that are almost always extremely stressed. However, the requirements for critical flange joints are even higher. There are not only bolts strength requirements, but strict leak rate requirements of gasket joint as well. This article provides a basic description of the effect of temperature on bolt pretension. Its theoretical basis is complemented by concrete examples from practice. Subsequently, one of the examples is subjected to FEM analysis. Finally, the possible ways of partial elimination of negative thermal influences on flange connections of pressure vessels are demonstrated.

This paper describes options of application of thin hard coatings on a non-standard involute HCR gearing made up of mat, 16MnCr5, in interaction with ecological gear oil OMV biogear S 150 and gear oil PP90H. Based on the analysis of their geometrical characteristic and it’s differences from a non-standard C-C gearing, the options of applying thin hard coatings on the surface of gear tooth flank are reviewed. From the previous results obtained at our workplace (Institute of Transport Technology and Designing, Faculty of Mechanical Engineering of STU in Bratislava) a TiAlCN nitride was applied and the article mentions the results obtained from Niemann’s stend for scuffing, which indicate that in the cases of lubrication with both OMV Biogear S 150 and PP90H similar results were achieved. The difference between the oils was only visible on the pinion, where scuffing occurred at the 12th load stage with OMV biogear S 150 oil at the dedendum, but with PP90H, no scuffing was observed.

Some types of bearings, which are used for specific applications of rolling bearings, allow the use of composite materials for cages. Generally, the cages are loaded only with small forces in rolling bearings, but at higher speeds or in disturbed rolling of bodies, the force acting on the cage can significantly increase. In these cases for increasing of elasticity of cages made from technical plastic are preferred, because they are well resistant to bearing lubricants. To improve the dimensional stability of these materials, they are reinforced with glass, carbon fibers, or glass microspheres, and alike. The cages made of composite materials are characterized by their low weight, high elasticity, and very good sliding properties. This paper presents the results of experimental research on the tribological properties of selected composite materials tested in different environments and their mutual comparison. Experimental measurements were realized on the experimental device linear microtribometer working on the principle of method ball on plane. This method according to the standard ISO 7148-2 is standard method for tribological properties testing. The structure analysis of experimental samples was performed because of understanding of potential structure influence on material properties. The aim of experiments was to acquire the knowledge that can be used in designing materials for bearing cages.

The article deals with the tribological properties of the heat-treated steel 100Cr6 and the nitride layer formed on this steel. Steel 100Cr6 is a bearing steel that is used to make bearings’ rings and bearings’ elements. The reason for the formation of nitride layer on heat-treated steel 100Cr6 is the decrease of the friction coefficient. The reduction of friction coefficient contributes to reduce wear and, at the same time, increases the lifetime of the rings and elements of roller bearings during their work time. Experimental measurements were realized on the experimental device rotary microtribometer working on principle “ball on disc”. The aim of tribological tests is to determine the coefficient of friction of material pairs, compare them and then evaluate them. Based on the results, the suitability of the nitride layer for the bearing materials is determined. The results will be suitable not only for bearing materials but also for a wide range of iron-based materials.

Qualitative determination of tribological properties of thin coatings, with the aim to test them for possible modification of friction in tribological for artificial human joints system, was done. Experiments were done at common conditions of laboratory environment and temperatures. Attention was paid to tribological characteristics of coated materials suitable for implants of human joints. Unique test apparatus and advanced measurement techniques AFM for experimental procedures were involved. The plane samples for experiments consist of three types of microstructures of steel 100Cr6 obtained after heat treatment. Samples with martensitic, bainitic, and sorbitic structure were coated with a hard and wear resistance WC/C coating. The coatings were deposited to functional surfaces of all plane samples. Magnetron sputtering method was used. As second friction body, a standard ball made of steel 100Cr6 was chosen. Received results extend the existing knowledge of tribology of thin layers. The friction processes in systems with high contact loads and the surface topography, using AFM microscope, were evaluated. The minimum friction coefficient values reached the level of 0.1–0.15; those are approximately 10 times higher as these for natural human joints. The lowest value of coefficient of friction was reached for WC/C coated samples with bainitic structure of the substrate.

The current situation on a field of 3D print does not allow significant changes in the printer’s construction. Usually, printer is equipped with definitive construction without ability to change parts. 3D printer’s build area is often a limiting factor, so there is a potential need for changing print area dimensions. The goal of this project is the design of modular construction of a 3D printer. In the future, that would mean, that after purchase and after query for increasing build area, it would be necessary just to connect another unified block. All the changes could allow rapid modification of the printer’s properties without increasing cost or rebuilding construction. As a result, it was able to develop a construction that is able to expand the build area at one axis. It is able to expand the build area with almost no limit in one direction. Expanding dimensions for more than one axis is a goal for the next research.

This chapter discusses the mechanical properties of samples made using 3D printing using Fused Deposition Modeling. At present, there is a great popularity of cheap RepRap 3D printers. One of these printers is Prusa i3 printers. The advantage of this printer is its low purchase price and low cost of ownership. This 3D printer allows infinitely many options for setting up 3D printing itself. The chapter describes Fused Deposition Modeling (FDM) printing technology, the use of materials, and the effect of setting up padding for printed items. The product is mainly aimed at adjusting the hexagonal charge of the measured samples and then evaluating the strength of these samples. It is known that a hexagonal structure called a honeycomb is the basis for lightweight cores. For usage of this hexagonal structure in conventional application, it is needed to know properties of material with different dimension. Measured values of material properties are evaluated at the end of this chapter.

Laser melting is one of the additive manufacturing methods that uses very strong ytterbium laser ray for the melting of very fine metallic powders to produce fully functioning 3D parts. The production process origins in 3D CAD model that is virtually divided into separate layers (2D curves—25 µm up to 100 µm thin). Sequential application of individual layers of metallic powder and its laser melting within the inert atmosphere creates 3D metallic part. We compared selected strength indicators of samples that were manufactured by the selective laser melting technology on AM 250 machine. The used material was AlSi10 Mg from two different suppliers. The comparison was also important in terms of economic efficiency, since the price difference between the two suppliers was up to 40%. Sample rods were produced by AM 250–200 W laser machine. Samples were cut after the prescribed heat treatment by annealing 300 °C ± 10 °C for 2 h with gradual air cooling.

Additive technology can cover both manufacturing and user segments. Common usage in households is only in its early stages and far from overshadows of industrial use. Additive technology offers economic benefits as well as simplification of logistics, minimization of inventories, guarantee of time flexibility, availability of spare and complementary parts, which redefine the lifetime of a common equipment. Individuality embedded into the production process, where any part produced by this technology can be customized according to customer’s specifications (within the certain limits), allows direct influence on the user’s surroundings. Innovative work that promotes uniquely creative design, as well as standardly shared templates, chosen materials, and their recycling, brings a range of options, which also entails certain risks. For the Smart City environment, it is important to secure sustainable efficiency for contained production systems. Utilizing methodologies such as EDSM [1] provides powerful tools for such technology management. To properly reflect the dynamic changes in a modern city, it is necessary to apply the principles of Industry 4.0. By implementing complete life cycle management, it should be possible to provide a secure future for additive technology as an indispensable part of a Smart City.

The paper presents three steps of process parameters development of aluminum alloy AlSi7Mg0.6 for selective laser melting (SLM) additive manufacturing process. Commonly, the components of AlSi7Mg0.6 aluminum alloy are produced by casting. However, to speed up the development phase of new products, often the SLM prototyping is used and thus the processing parameters for this material are required. To develop process parameters of new alloy, single weld tracks were used followed by thin walls and cuboid samples. The cross sections and continuity of single-track welds were evaluated within the range of 200–2000 mm/s laser scanning speed and 175–400 W laser power. The tracks with good size and quality were chosen for further analysis. To minimize the porosity of material, cuboid samples with different overlap of weld tracks were evaluated. The overlap of approximately 80% was found to produce suitable samples with porosity below 0.5%. Finally, the mechanical properties of samples without heat treatment evaluated by tensile testing reached 380 MPa of ultimate tensile strength (UTS), which is slightly higher than cast alloy in T6 state.

New types of flood barriers must be tested before they are approved for use. One of these tests is the impact of a wood log. Implementation of this test is very difficult because the real wood log is very heavy and large and the test is very space consuming. Therefore, the special test device was built under the project VI20152018005 of the Ministry of the Interior of the Czech Republic. The wood log impact is simulated by a pneumatic engine with impactor head and this engine is controlled so that the impact to the tested flood barrier has the same speed and energy as the impact of the real wood log. It means the impact energy must be evaluated in real time during the test and the engine movement is stopped when the set energy value is reached (these parameters were obtained during impact tests with the real wood log). The design of the system for the pneumatic engine controlling is described in this article.

The filtration process using porous structures (foams, textile structures, granular materials…) is very complicated and its understanding is important for the production of filter materials for a maximum efficiency, low pressure drop, and filter lifetime. To obtain comprehensive information systematic analysis of the structure of the filter media by image analysis of images obtained by optical and electron microscopy, and through micro-tomography were conducted. In particular, it was the characterization of the morphology and structure incl. directional arrangement, fiber diameters, and pore shape as well as porosity. Based on this information, 2D CAD models were created representing the filter medium with the corresponding parameters. Real filter medium was tested on the experimental test device in order to determine pressure drops at different flow rates. These values determined the boundary conditions of the numerical model and the control values for the verification of the model. The result is a numeric model depicting the water flow depending on the depth and the complexity of the filter. The model shows a very good match with the experimental results. It could significantly help to design the structure of the filter media.

Nowadays, technologies like winding, braiding or wrapping of high-strength fibers used for manufacturing composite materials are used by producers in almost all sectors. This thesis describes a method of the prepreg (pre-impregnated) carbon filament winding with regards to manufacturing and effective designing of curved rods (elbows). The process of winding fibers is known for a long time. However, until recently was this technology used especially in the field of textile engineering, braiding of ropes, hoses and similar parts from atypical sectors. The basic elements of traditional filament winding are a non-bearing mandrel and spools. In the studied case of winding, the mandrel stands on a place and the spools with fibers rotating around and simultaneously moving parallel to it. The fiber can be wound in helical, circumferential and polar pattern with geodesic or non-geodesic behavior. However, when winding profiles with curved shapes, there could be significant deviations between the real and desired winding angle, caused by the irregular distribution of fibers on the inner and outer tube radius. Therefore, the aim of this work is to describe this phenomenon and find out an optimal solution on how to assure the constant mechanical parameters through the entire shape. The process has been described analytically and also simulated with using specialized software CADWIND.

The development of composite materials for weight reducing is a trend in transport and other industrial areas. The composition of the composite material generates a synergistic effect that provides their advantages. The composite consists of a dispersive and continuous phase. For composites, different fibers (carbon, glass, basalt, textile and natural fibers) and plastic matrices with specific properties can be applied. The type, quantity and arrangement of fibers in the composite are designed for strength characteristics depending on the maximum applied load. Samples of the composite material were made by fiber winding technology on non-bearing core with required geometry. An image analysis of the structure and morphology was performed by scanning electron microscopy (SEM). The study of matrix penetration among fibers has shown that the directional fiber winding production technology in the case of uncontrolled winding significantly affects the resulting ratio between fiber and matrix area. This was reflected in the standard tensile, bending and impact tests by a reduction of mechanical properties of the resulting composite. Insufficiently, saturated areas create the source of defects and crack propagation in the composite. Mechanical properties were determined from numerical models. The nature of strain and stress distribution in individual layers have been identified. The results of the mechanical tests were compared with the numerical model. A comparison of experimental results and numerical models shows that fully controlled winding allows increasing mechanical characteristics of the resulting composite. The cause can be found in the optimal distribution of the fibers in the composite.

The paper discusses the issue of enhanced boiling heat transfer with the use of metal mesh microstructures. Such heat exchangers can significantly increase heat flux value dissipated during pool boiling. It is especially vital for the production of efficient phase-change heat exchangers used e.g. in refrigeration or electronic cooling. The article provides special focus on a selected heat flux determination method and presents the comparison of the chosen calculation technique with the experimental data of nucleate boiling heat transfer on copper meshed surfaces under ambient pressure. The considered boiling agents and distilled water and ethyl alcohol. The comparison has proven that the congruence between experimental and calculation results may be satisfactory, but not for all the data. Thus, a more reliable model or a correlation that could more successfully determine the heat flux value based on material and geometrical parameters of the microstructures is still needed to be developed.

This paper discusses the effect of selected parameters of laser welding on the mechanical properties of welds. Two parameters were analysed: the welding speed and the laser power. The properties of the material in the fusion zone and the heat-affected zone were determined by performing static tensile tests, hardness tests and microscopic analysis. The welding was carried out using a CO2 laser (wavelength λ = 10.6 μm). The specimens were 0.8 mm in thickness, and they were made of DC04 steel. The results indicate that welds produced at different welding parameters have similar mechanical properties. The experiment was conducted and analysed according to requirements of the design of experiment methodology. Laser beam welding allows us to join various dissimilar metals, which have not been possible with conventional methods. It should be emphasized; however, that not all metals are suitable for laser welding; it all depends on their thermal and structural properties. For example, tin, aluminium, lead, tantalum and tungsten are generally difficult to weld.

The determination of the mechanical properties of the designing materials is carried out in various ways by using standard procedures. The basic test is the tensile test, from which it is possible to determine directly Young’s tensile modulus-E [Pa]. Some materials can not be tested by this procedure. These are mainly building materials (concrete), some plastics and composites, glass and ceramics. The biggest problem of these materials is the clamping of the ends of the test specimens in the jaws of the tearing machine. The tensile test is replaced for these materials by a bending test to determine the mechanical properties. The bending test can be performed with a simple supported beam, which is loaded with alone force—it is a three-point bend test or a beam that is loaded with a pair of forces—it is a four-point bend test. The bending modulus and the stiffness characteristics of the material are results of measurement. Bending modulus can be recalculated using the cross-sectional characteristics of the test specimen to the tensile modulus. The article describes the basic differences between the two variants of the bending test, the course of loading and deformation. The results obtained by measuring on composite specimens were verified using mathematical models and their degree of agreement was determined.

This article deals with the design a manufacturing of belt wheel for bicycles, with the help of 3D printing. The market with bicycles, that use belt instead of a traditional chain, is growing steadily. In the design process of a new bicycle model, you need to quick check, if the proposed belt wheels fit into the frame. Even in time of 3D CAD applications, a physical check is necessary to confirm the design. Also, a physical model is helpful to tray the assembly process. For small companies, it is expensive to buy multiple belt wheels, with different tooth numbers, just to confirm the proposed design. On the other hand, some companies want to use her own belt model, for which is no belt wheel for bicycles. Here comes 3D printing handy. This method if fast and flexible, and in small series can be cheaper then belt wheel made by traditional methods. This article deals with the problem of designing a belt wheel from a given belt model and different 3D printing methods for their production.

This study analyzed the performance of a pelleting machine with a manual feeder and with a horizontal rotating matrix. Hazelnut husk residue obtained after hazelnut harvesting is used as a material. The residues were pelleted at M10 moisture content and with 6 mm particle sizes. Physical properties (bulk density, pellet density, mechanical duration and pellet firmness, moisture and equivalent humidity contents) and thermal properties (gas emission values after combustion, ash content and calorific values) of the pellets were measured. Pellets bulk density was 584.44 kg m−3. Particle density, mechanical durability and firmness values were 1238.20 kg m−3, 93.26% and 1146.00 N, respectively. Regarding the emission values, the pellets’ flue gases were within the legal limits and had a heating value of 4196 cal g−1, which is close to the heating value of wood. In conclusion, the pelleting machine with a horizontal rotating matrix was found to be very suitable for pelleting hazelnut husks, and this means that this agro-based residue material can be readily used as a solid fuel.

The paper deals with the innovation of the device for nanofibers producing from a free surface of polymer solution. The collector (negative electrode) is one of the main parts of the device. The original flat collector did not provide sufficient results at producing 3D nanostructure. The production of 3D nanostructure demands high intensity of electrostatic field (big force) for obtaining sufficient productivity but at the same time low intensity of electrostatic field (small force) for obtaining required 3D nanostructure at the collector. This problem can be solved by the use of the method Theory of Inventive Problem Solving (TRIZ) and its tools for physical contradiction solving. The defining of the physical contradiction, resolving the contradiction by the use of separation and also inventive principles (especially principle nr. 9 Preliminary anti-action) are described in the paper. The idea of collector innovation has been confirmed by the numerical simulation FEM and verified by the experimental way.