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Geometric deviations play a crucial role in the quality of additive manufacturing, particularly in parts made with biodegradable resins. Accurately controlling dimensional and geometric variations in manufactured components is critical for achieving defect-free production and meeting functional standards. However, defining a final quality score can be challenging due to numerous dimensional and geometric deviations associated with a part. An innovative metric for evaluating geometric performance was created to measure dimensional precision in components produced through VAT photopolymerization. The index measures the dimensional and geometrical deviations, revealing that external surfaces exhibit greater precision than internal ones. This difference is likely due to internal surfaces overcoming heat dissipation challenges during the cooling process, resulting in less shrinkage for external surfaces. This index is essential in various stages of the manufacturing process, including part design, design for manufacturing and assembly, quality assurance, and process planning, helping to select the appropriate additive manufacturing technology and optimal process parameters.

This paper deals with the design of a multi-part mould for the production of a carbon fibre medium-large compo-nent. The design and forming of a medium-large component which is defined by a closed structure and has high demands on dimensional accuracy is a very complex process. The goal was to design a simple manufacturing pro-cess for a negative mould. There are many different ways to design and manufacture this type of mould. One pos-sible solution was designed and tested. This paper describes the case study of a carbon fibre monocoque of a small racing car. The first step was to define the requirements of the final product and the negative mould. The next step was to design a multi-part mould with one main parting plane and two minor parting planes and define the number of steps needed to build a negative mould. Another problem is how to define the position of the general anchor points that determine the final product. In this case the procedure of transferring the hole from a positive to a negative mould was defined.

The conventional milling cutter design is based on a solid body. A cutter designed in this way has a guaranteed rigidity, but at the expense of tool dynamics. Computational methods of designing reduce the mass of a cutter in locations with lower stress density. This approach increases stiffness relative to the weight of the cutter. This paper analyses the benefits of modifications in the design of a lightweight cutter. The design uses an envelope of a con-ventional milling cutter that is filled by walls. Each modification changes the elasticity in different directions. These changes are monitored by displacements at the centre of the cutting inserts under load. Simulations confirm that even a small weight gain can mean a significant increase in tool stiffness.

With the development of 3D technology, more and more materials are being used for manufacturing and used in many fields, such as factory manufacturing, workshop manufacturing, food packaging, and even architectural design and civil engineering design. In particular, the mechanical properties of the 3D printed HIPS polymer unit cell structure are worthy of research and analysis, providing more valuable references for future material development. This study focused on the properties of HIPS polymer materials and the performance of HIPS polymer 3D printed lattice structures after Instron instrument compression testing. The experimental samples were divided into 4 groups and there were 4 different experimental variables for analysis and comparison. Finally, it was found through analysis that the HIPS polymer material has good compression resistance, and the structure is relatively stable. It can be used more in the fields of manufacturing, architectural design and civil engineering in the future.

This article is aimed at design of a support and a tension mechanism to be mounted on a wheel-tracked chassis of a mine clearing machine. The subject machine serves to detect and disposal mines in terrain. The main advantage of this machine is the possibility to use it from the safe distance thanks a remote control. The wheel-tracked chassis mounted on the machine ensures that the machine is able to overcome extreme obstacles of a terrain. The solved design of the wheel-tracked chassis can be modifying to move using just wheels for better driving properties on metalled roads. Current design of the wheel-tracked chassis goes out from the older technical solution, which has been designed for a four-wheeled machine. The latest version of the chassis is designed for a six-wheeled machine. Application of an original structure of the chassis meets problems consisted in formation of ckacks in tracks struc-ture therefore the current structure of tracks has to be modified in order to meet all requirements in term of strength and long-term operation. At the same time, two design of a tension mechanism are presented. A tension mechanism is additional device, which will be mounted to the chassis and it will ensure the optimal position of tracks in every load case.

The article deals with the measurement of the vibrations in passenger elevators. The introduction of an article briefly discusses machine vibrations and their impact on machine design and the surrounding environment. The basic equations from which the equations of motion are derived are listed here. The importance of analyzing machine vibrations in their design, or rather proposing solutions to reduce vi-brations during machine reconstruction, is emphasized. Specifically, attention is paid to vibrations gen-erated during an elevator operation in the elevator shaft. This is an elevator for transporting people in a newly constructed 5-story building. Vibration values generated by an elevator operation were measured in order to assess the suitability of simple anti-vibration modifications. Vibration measurements were taken on an existing elevator without modifications, and after the initial measurements, modifications were made to attach the guides to the bracket and attach the bracket to the elevator shaft wall. After the adjustment, the vibration measurement was performed again and both measurements were compared with each other.

This study investigates the susceptibility of two pipeline steels, ferritic–pearlitic CSN 12022 and martensitic L80, to hydrogen embrittlement. Electrolytic hydrogen charging increased the absorbed hydrogen content approximately fivefold in both steels, with the martensitic grade showing higher uptake due to its dense dislocation network and carbide distribution. Tensile tests demonstrated that hydrogen had little influence on yield or ultimate tensile strength but caused a severe reduction in ductility. Elongation dropped from 39 % to 13 % in CSN 12022 and from 25 % to 11 % in L80. Fractographic analysis confirmed a transition from ductile dimple fracture to quasi-cleavage fracture in the hydrogen-charged condition. These findings confirm that microstructure strongly affects hydrogen embrittlement: ferritic–pearlitic steel undergoes a more dramatic relative loss in ductility, while martensitic steel retains higher strength but exhibits significant hydrogen-assisted cracking. The results highlight the importance of considering hydrogen effects in the design and application of steels for energy and gas transport systems.

The main idea of this research work is to understand the energy absorbing capacity of cellular solids when used in application of automobile as a safety measure to protect the occupants and structure of the vehicle. The full scaled model of the proposed design of the impact attenuator would be an expensive approach to follow. To understand the mechanism of energy absorption in honeycomb structure two types of experimental test were carried out. The first test includes a simple compression test of honeycomb structure only. The second experimental test consist of a composite sandwich of glass fiber and honeycomb under high speed drop test. Using the simple compression test the mechanical properties of the honeycomb were extracted in the out of plane behavior and then results from experimental data were calibrated with the FEM model. It was observed that very similar results were obtained in Experimental and FEM methods. And finally, the full scaled model analysis was carried in FEM package of ANSYS using mechanical properties of honeycomb extracted in simple compression test.

This paper carries out the simulation of abrasive flow for twist drill spiral grooves and the experimental study of abrasive flow polishing. The flow of abrasive in spiral groove in abrasive flow polishing twist drill was analyzed by CFD using FLUENT software. Different inlet speeds and abrasive concentrations were used as parameters for simulation calculations to obtain the state parameters of dynamic pressure and abrasive velocity in the flow channel, and to analyse their effects on the abrasive flow in the spiral groove. The analysis results show that the dynamic pressure in the twist drill spiral groove increases with the increase of inlet speed, and becomes smaller as the abrasive flows along the spiral surface. Under the condition of different abrasive concentrations, the velocity of abrasive decreases with the increase of abrasive concentration. Under the same abrasive concentration condition, the abrasive velocity decreases gradually from inlet to outlet. For actual processing, the abrasive concentration can be selected between 50-60%. Based on the simulation analysis results, the parameters of abrasive flow polishing process were set, the orthogonal test method was adopted, and the test data were analysed by the polar analysis method the results showed that the priority order of the influencing factors of spiral groove polishing was: abrasive type > inlet speed > polishing time. Using SiC abrasive, inlet speed 0.5 m.s^-1, polishing time30 min, the surface roughness of the spiral groove of cemented carbide twist drill after polishing is the minimum, reaching Ra0.189, which is far less than the design requirements.

Additive manufacturing (AM) is rapidly developing with emerging technology of wire arc additive manufacturing (WAAM) process due to its ability to manufacture large components and high deposition rate. However, WAAM faces mechanical properties problems like porosity, distortion, and strength due to the large heat affected zone (HAZ) from commonly used heat sources such as metal inert gas (MIG) and tungsten inert gas (TIG). Utilization of micro plasma as the heat source should reduce this problem since it has a smaller heat source diameter. Therefore, this study investigates the thermal distribution of micro plasma wire arc additive manufacturing (MPWAAM) by developing a finite element method (FEM) model. This paper focuses on the fabrication of single-layer multitrack deposition and tool path planning of multi-layer multitrack depositions by MPWAAM process. The melt pool size and peak temperature are mainly governed by heat input per unit travel speed of the worktable, with current and voltage being the significant factors. Besides, tool path planning strategy influences the properties and quality of the final product, where parallel tool path design with longer interlayer cooling time minimized part distortion and residual stresses.

Fisheye contact pair is an important component of board level interconnection products wide range of applications. However, insertion and withdrawal force have great influence on the contact deformation due to their small size and complex structure. In this paper to the fisheye contact pairs of interconnection products as the research object, the main parameters were analyzed which could affect the contact deformation of fisheye structure, and factor analysis of them were performed. And three relatively more significant factors were extracted. The simulation based on Response Surface Methodology (RSM) is designed, And the experimental data was conducted regression fitting, getting the second regression model. The established quadratic regression model was analyzed based on MATLAB and the response of various factors on the insertion and withdrawal force, then the optimized parameter model of fisheye structure was obtained. The research shows that the quadratic regression model based on response surface methodology fitting accuracy was high and there were good practical value about it.

Plastic materials are used in automobile, electrical and electronic applications, agricultural utilization, household and furniture products, and medical equipments. Among various plastic manufacturing process, injection molding is one of the most commonly used and common methods applied for forming plastic products in the industry. The process requires a molten polymer being injected into a cavity of a mold, which is cooled and the product ejected from the mold. During the Plastic Injection Molding (PIM) process, various defects, such as volumetric shrinkage, warpage, weld line and sink mark can occur. This paper presents a method to minimizing warpage defect on PolyPropylene AZ564 via PIM simulation using Moldflow software. The approach was based on Taguchi method.
Through the effectiveness of this proposed method, it is confirmed using simulation by Moldflow software. The effect of the process parameters on the warpage of a motorcycle number plate bracket, is studied using analysis of variance (ANOVA). From the ANOVA, the significant parameters affecting the process are holding time, holding pressure and injection pressure. The result of the Taguchi prediction shown that minimum warpage is 1.078 mm, which is 7.14% and 9.09% different from the simulation result and experiment, respectively.

Generative design is one of the most promising means of new product development in the world. It allows formation of organic structures that brings various benefits, e.g. in the form of savings of material and production costs. Generative design includes several types of technology, topological optimization included. The paper addresses the technology of topological optimization implemented on the support part of the 3D printing pad. The result of optimization is the creation of a new, more suitable design concept through the Altair Inspire optimization software.

This article deals with the comparison of the wear of indexable CNMG carbide inserts from two dif-ferent manufacturers when turning austenitic stainless steel 1.4404, which is not intended as the pri-mary material to be machined from the point of view of the tested inserts. The main goal was to demonstrate the different course of wear by testing inserts of the same type according to ISO 6987 showing the connection between the design and processing of the inserts in connection with the se-lected cutting parameters. The monitored type of wear was the main flank wear VBmax, depending on the length of the machining time. Optical and electron microscopes were used to analyze the flank wear. According to the assumption, it was found that the layout of the cutting edge geometry and coating layers has a noticeable effect on the degree of wear of the evaluated cutting inserts. At the same time, it was found that the tested indexable inserts achieved very good service life values de-spite the fact that the tested material does not belong to the primary use group. Evaluation of cutting tool wear has a significant economic potential for manufacturing companies seeking to minimize costs by trying to use as many universal cutting tools as possible or looking for opportunities to ex-pand the applications of already used cutting tools.

The article presents the method of investigating the pressure distribution on uneven surfaces, used for the development of a new, modern series of school furniture that meets the relevant health, pedagogical and legal requirements. During the examination of pressure conditions on school chairs with a flexible tactile sensor, which was primarilly developed for this purpose, exact data on the immediate differences in contact pressures between the person sitting and the seat are obtained. Based on this information, it is then possible to optimally shape the seats during their design and subsequent production according to the age of the sitters and the needs of the organizational form of teaching from the point of view of the specific character of the teaching environment. Technical parameters of the flexible tactile sensor depend on the shape and number of electrodes, as well as on the conductive inks used, they are stated and dis-cussed within the article. Due to the large number of collected data, a robot, otherwise used in teaching, was used for obtaining of individual loading characteristics of the proposed sensor. At the end of the article, the results obtained by the statistical processing of the measurements are summarized and dis-cussed.

The three-point front-mounted electric forklift is an important logistics tool nowadays. The wheel-side reducer is a vital power unit of the electric forklift. The cover plate of the reducer casing, as a key component, bears significant external loads. The cover plate of the casing is prone to deformation under the action of loads, leading to part scrapping and reducing the service life of the entire machine. Additionally, as the cover plate directly connects with the vehicle body, vibrations produced by the electric forklift during operation can affect the working stability of the reducer through the cover plate, reducing its lifespan. When designers design the wheel-side reducer cover plate, they first establish a 3D model of the cover plate using Pro/E. Then, the 3D model is imported into the finite element analysis software ANSYS. By integrating the Newton-Raphson iterative method, the cover plate undergoes static analysis, predicting potential design flaws and proposing corresponding optimization strategies. After several rounds of simulation and optimization, the cover plate meets the usage requirements. Through modal analysis, the inherent frequency of the cover plate is determined. This allows for the assessment of the relationship between the working frequency and inherent frequency, thus facilitating the improvement of the cover plate's design parameters to reduce resonance and noise. Through static and modal analysis, not only is the design cycle of the reducer cover plate shortened and production costs lowered, but resonance is also minimized, enhancing the working stability of the reducer.

The main parameters of the hot forming machines are production capacity and the fatigue life of the used tools. The life of a tool depends on its shape and load. The load depends on the structural design and speed of forming. The goal of our paper is to present the structural optimization and technological parameters design with respect to tool life. This process is applied in the case of the hot forming machine analysis.

With the increasing demand for high-quality flange, there is a greater need for high-quality and high-speed machining technology. Aiming at the difficulty of surface roughness in meeting design requirements and poor machining stability of 7075 aluminum alloy, the classical Design of Experiments (DOE) method is employed to optimize the machining parameters and identify eight pertinent factors. By selecting the feed rate and cutting speed as the two significant factors, a  mathematical model of roughness is derived, and the theoretically optimal machining parameters are determined. According to corresponding experimental results, the roughness, the parallelism of the two end faces of the flange, and machining efficiency, in order to further validate the accuracy of the model. The final processing parameters are 0.07 mm.r^-1 feed rate and 1100 m.min^-1 cutting speed, which provide a reference for actual production.

This work deals with the construction design and manufacturing of a cylinder liner which is used in a Jawa 50 motorcycle in order to increase the performance characteristics. The liner is pressed in the aluminium cylinder case with ribs so together it makes a two-stroke motorcycle cylinder. The first step was to build an analysis of the technical design of the original motorcycle cylinder to detect any restrictive parameters for the modifications, especially of the cylinder liner, so the motorcycle can be used for racing. As well as the construction design of the liner, the work deals with the clamping and manufacturing of this part too. The CNC code was written using SolidCAM software. Then the liner was manufactured in a turning-milling centre. The purpose of this work is to produce a liner so that it forms a racing motorcycle cylinder together with the aluminium case with the ribs. The basis of this project is the correctness of the construction design and the accuracy in manufacturing so that the engine can achieve the demanded parameters with respect to usability, engine cooling, gear setup, engine life and the other restrictive parameters.

The proper design of the gating system including the tempering and venting of the mold significantly influences the final quality of the casting and economize the costs of the foundries. The initial numerical design of the gating system is often sufficient for creating of the documentation for the mold design, but without the practical experience of the designer, it does not reveal the hidden problem emerging from the melt flow through the gating system as well as the temperature and gas mode of the mold.The contribution is dedicated to the optimization of the runner dimensions determined by the numerical calculation. The theoretical part presents the methodology, based on which the gating system was designed for a particular type of the pressure casting. The experimental part is dedicated to the influence of the cross sectional area of the runner on the change of the melt temperature before entering the ingate. It was assumed that the larger runner cross section gives the melt greater volume and heat capacity and thus the melt enters the ingate with the higher temperature. The obtained temperature results are then compared witht he melt flow rate values, based on which an optimal sulotion for the runner design dimensions is determined.

In response to the need for trajectory correction during the excavation of curved tunnels by tunnel boring machines(TBM), as well as the impact of interference forces generated by the propulsion sys-tem on the design and service life of key components, as well as the low propulsion efficiency of TBM, a dynamic model of the propulsion mechanism during the excavation process is established, and the variation law of the angle between the key components of the thrust hydraulic cylinder and the gripper shoe hydraulic cylinder under the propulsion force of the hydraulic cylinder (1500KN) and three steer-ing angles of 0.5 °, 1 °, and 2 °, as well as the relationship between the gripper shoe hydraulic cyl-inder tightening force and horizontal propulsion force, has been studied. Research has shown that under the rated hydraulic cylinder propulsion force, during the process of increasing the swing angle of the main beam, the left angle and the tightening force on the left gripper shoe are less than the straight-line working condition, while the right side is greater than the straight-line working condition. However, during the forward excavation process after turning left, the X-direction propulsion force provided by the left thrust cylinder is greater than the X-direction propulsion force of the horizontal excavation, and the force on the left support shoe is less than the tightening force under the horizontal working condition, while the opposite is true for the right side. The research results have important theoretical significance for studying the optimal matching relationship between the mechanical model and excavation parameters of TBM during the propulsion process, as well as further improving the excavation efficiency and stability of TBM.

The article describes a pilot experiment of mechanical testing of 3D printed vertebrae with an inserted screw. The main goal of this work was to verify the design of a measurement methodology for experimentally determining the mechanical properties of vertebrae produced using 3D printing and also for determining the load-bearing capacity of a screw when it is drilled into a vertebra. The work describes the construction of a special fixture with which it is possible to clamp test samples for tensile testing. The stud screws were pulled out of a real or printed vertebra using a tearing machine. Testing was performed on porcine and 3D printed vertebrae. CT images of porcine spines obtained by a computed tomography scanner were used to create the printed vertebrae. This work verified the mechanical properties of printed and real vertebrae. In connection with this work, suitable printed materials and the necessary parameters of 3D printed samples will be sought so that they correspond to the necessary mechanical properties and can replace human vertebrae. It will then be possible to conduct laboratory investigations to obtain better results in spinal stabilization. The experiments verified the measurement methodology, compared the measured values between real and printed vertebrae, and also determined the next direction of research.

The industrial use of aluminium alloys has significantly increased in the last decades. Most machined parts are produced by cutting. Therefore, research in this field is quite important nowadays. Surface roughness is an extremely important quality parameter of a product, such as geometrical sizes and their tolerance. The authors in this article analysed the machinability of die-cast aluminium alloys with silicon often used in the industry. The turning experiments were made with different diamond tools edge geometry. The surface roughness obtained during turning was analysed in detail. Phenomenological models were created with which the surface roughness producing ability of the examined tools can be estimated in technological design.

ŠKODA VÝZKUM cooperated on the development of the NEOPLAN DMA low-floor articulated trolleybus intended for the Boston city (the United States). Multibody models and finite element models of the trolleybus were utilized in the stage of the vehicle design. The multibody models of the trolleybus were created in the alaska simulation tool and the simulations were especially aimed at determining forces acting in the trolleybus suspension elements and radius rods. At the end of the stage of computer modelling and testing the trolleybus prototype a decision to change the type of shock absorbers used in the axles' suspension was made. The impact of this change on forces acting in the trolleybus suspension elements (i.e. in air springs and shock absorbers) and radius rods on the trolleybus chassis when running on an uneven test track was investigated using multibody simulations. Time histories of the forces calculated utilising multibody models were used as input data of the trolleybus finite element models. Stress in the critical places of the trolleybus body structure was determined utilizing the finite element models.

Cycloid gear drive is widely used in robot cycloid planetary reducer, and the transmission accuracy is the key property of the reducer. The standard cycloid transmission is a multi-tooth mesh. The modification method has attracted extensive attention as one of the important parameters of the cycloid drive. The influence of the isometric and shifting modification of the cycloid gear on the cycloid transmission backlash was analysed according to the characteristics of the multi-tooth mesh and the profile equation of the modified cycloid gear in this study. Combined with the backlash analysis, a multi-objective optimization mathematical model of cycloid gear modification parameters was established to ensure the backlash and strength of the reducer. The study showed that the modification combination mode and parameters were obtained under different application conditions, thus providing a certain reference for the modification parameter design of cycloid transmission.

The design of the formwork support for a certain section of the Beijing subway project was carried out in this paper. And the disk lock formwork support was used in the engineering.It was analyzed on the the design of the formwork support for the roof with the thickness of 1.5m of the interval engineering. The manual calculation and the sap2000 finite element analysis were also used in the paper.The effect of the diagonal brace and its number were analyzed in addition to the design of the formwork support. It was showed that the axial force of the standing tube tends to be uneven with the increase of the number of slant bars in the framework. And the axial force of the standing tube connected to diagonal brace is larger than that of the framework without brace significantly. So it will be dangerous to the framework without considering the effect of it by the manual calculation.

There is a lot of applications for manipulating industrial robots nowadays. Maximizing the tasks that can be assigned to robot manipulators is one of the criteria for deciding if their application is appropri-ate. The article discusses the topology optimization of the gripping jaws of an industrial robot to reduce the jaws' weight. The previously used gripping element made of C50E steel was optimized to reduce the weight of the jaws. Shape optimization was performed based on analysis from CAD programs Inventor Professional 2022, Autodesk Fusion 360, and Ansys Discovery. The new jaws were manufactured by the additive technology of selective laser sintering (SLS) from PA12 material. The optimization resulted in a significant reduction in weight compared to the original jaws. As a result of optimizing the weight of the designed jaws, it was possible to increase the weight of the object of manipulation.

Main aim of this paper is to analyze the thermal behavior of different cooling channels and to describe advantages of manufacturing of a mold with these channels using a 3D printer instead of drilling machines. This work was primarily done by the usage of virtual simulation. Validation of thermal simulations was performed by usage of simple analytical solution. A simple model of molded brick was designed to analyze the cooling time and the temperature distribution in the mold when changing the cross section of the cooling channels. Three types of different rectangular cross-sections and one circular were chosen. All of them have the same area. The cooling channel with circular cross section was positioned closer to the part in next design and influence of this change was analyzed. Last tested configuration is conformal cooling channel with a channel path twice longer. It is obvious, that most suitable configuration of cooling channels is combination of conformal design with rectangular shape as close as possible to plastic part.

In the urban railways environment, there is considerable stress of the track due to operation, which results in extensive deformation of the track geometric position, wear of the rail heads, expansion of the free channel of the track, leading to an increase in steering forces in the rail-wheel contact and further worsening of the situation. The authors perceive this situation primarily as a consequence of an inappropriate bogie concept of the operating vehicles - not of the track quality. The article focuses on designing a new bogie concept that takes into account the specific environmental conditions for which it is intended. The presented bogie design is characterized by the mounting of the frame on the wheelsets by means of three bearing boxes and the presence of a mechanism for adjusting the radial position of the wheelsets during ride in track arcs. This is a new, unconventional solution for which a number of patent applications have been filed. Simulation analyzes of vehicle ride with the designed bogie are currently underway. On the basis of the first results, it is foreseen that the design will increase the life of the track several times, reduce the energy consumption of vehicles and the environmental load of the environment through the transport system.

FDM forming 3D printers may encounter problems such as rough printing surface and poor accuracy during operation. This study mainly utilizes the complementary advantages of piston extrusion mechanism, sliding vane pump extrusion mechanism, and plunger pump extrusion mechanism to design a parallel combination of three nozzle extrusion mechanism, and conducts simulation experiments to verify its effectiveness based on temperature distribution data comparison. It basically avoids the irregular voids and faults caused by the thermal phase change of materials passing through the nozzle during the printing process.