In recent years, plastic and metal 3D printing has experienced massive development in the professional and hobby spheres, especially for rapid prototyping, reverse engineering, maintenance and quick repairs. However, this technology is limited by a number of factors, with the most common being the cost and availability of the technology but also the lack of information on material properties. This study focuses on investigating the material properties of PLA, PETG, HIPS, PA, ABS and ASA in order to elucidate their behavior in terms of wear and thermal resistance. The research builds on previous studies focusing on the mechanical properties of these materials and includes wear testing and DMA analysis. Weight loss, frictional forces, and frictional work including relative frictional work are recorded as part of this testing. The storage modulus and loss modulus including tan(δ) were then measured using DMA.

Considering a fuzzy graph G is simple and can be connected and considered as a subset $H=\left\{\left(u_1,\sigma \left(u_1\right)\right),\left(u_2,\sigma \left(u_2\right)\right),\dots \left(u_k,\sigma \left(u_k\right)\right)\right\}, \left|H\right|\ge 2$; then, every two pairs of elements of $\sigma -H$ have a unique depiction with the relation of $H$, and $H$ can be termed as a fuzzy resolving set (FRS). The minimal $H$ cardinality is regarded as the fuzzy resolving number (FRN), and it is signified by $Fr\left(G\right)$. An independence set is discussed on the FRS, fuzzy resolving domination set (FRDS), and Fuzzy modified antimagic resolving set (FMARS). In this paper, we discuss the independency of FRS and FMARS in which an application has also been developed.

This article discusses the issue of force behavior in a pre-tensioned bolt that is part of a symmetrical flange connection, loaded with an operating load parallel to the bolt axis. The first part describes the issue being dealt with in detail. The next part offers a brief description of the generally known theoretical approach to the solution, and also outlines the limitations of this approach. This part is followed by a theoretical analysis of working load behavior in the bolt of the analyzed device, using Finite Element Method (FEM). In this article, a comparison of several different approaches to the solution can be also found, followed by a description of the experiment preparation and its results. The obtained values also serve as a subject for reverse iterative analysis carried out using ANSYS software. The aim is to find a proper modification to the symmetric calculation model that would be consistent with the results of measurements from technical practice. All results achieved are described in the final part of the article.

In recent years, topological optimization has become a powerful tool for designers and engineers in the technical world. The principle of this method is based on optimizing a given optimization region by minimizing or maximizing one or more objective functions, e.g. stiffness, mass, or natural frequency of the structure. For this reason, software companies developing CAD or FEM software have included topological optimization in their portfolio, either as a modular part of the software or as a dedicated program. In general, users of these programs do not have a mathematical definition of the software background, and it is not clear what variations in calculations may occur when using different software. For this reason, a comparative analysis of the selected software was performed to determine the differences between the results assuming the same boundary conditions and machine parts such as computing time, weight and volume.

This paper deals about experimental determination of changing the axial load in the bolts of the clamping sleeve under its axial load. Inspiration for this experiment was FEM analysis clamping sleeve in Ansys workbench. Changing of the axial load in the bolts is very important for fatigue of bolt. Bolt force and pretension is necessary for transmit axial load and torque. the change occurs when the sleeve is loaded by the axial force.

In the vast majority of technical applications, there is a necessity to transmit the torque from drive to driven machine together with the demand to overcome great distance between given devices. One of the solutions of this problem is the use of a cardan shaft. Operations of connecting shaft and drivetrain are accompanied by oscillations negatively influencing the driver comfort. Main subject of this article is the measurement of vibrations on different parts of a heavy truck and its evaluation by FFT analysis. Measurements are performed with two kinds of suspension bushing which are compared with to each other. Based on the previous measuring, influence of cardan shaft length was also investigated. First of all, dependency on the length of the cardan shaft on deflection angles for V arrangement was evaluated by analytical method. The theoretical introduction is followed by research of eigen frequency depending on the length of the cardan shaft. The results obtained by modal analysis in FEM are verified by experimental modal analysis [1].