Structural size optimization of a device for external bone fixation within a formed iterative hybrid optimization algorithm was presented in this paper. The optimization algorithm was in interaction with the algorithms for generative design and FEM analysis and completely integrated within CATIA CAD/CAM/CAE system. The initial model, representing the current design of the bone external fixation device Sarafix, was previously verified by experimental testing. The formed hybrid optimization algorithm was created as an integration of the global (SA method) and local (CG method) algorithm. The constraints of the optimization model are the clinical limitations of the interfragmentary displacements and the material strength. The optimized design has less weight, greater rigidity and less transverse interfragmentary displacements at the point of fracture compared to the current design.

This paper presents the development and experimental verification of a generative CAD/FEM model of an external bone fixation device. The generative CAD model is based on the development of a parameterized skeleton algorithm and sub-algorithms for parametric modeling and positioning of components within a fixator assembly using the CATIA CAD/CAM/CAE system. After a structural analysis performed in the same system, the FEM model was used to follow interfragmentary fracture displacements, axial displacements at the loading site, as well as principal and Von Mises stresses at the fixator connecting rod. The experimental analysis verified the results of the CAD/FEM model from an aspect of axial displacement at the load site using a material testing machine (deviation of 3.9 %) and the principal stresses in the middle of the fixator connecting rod using tensometric measurements (deviation of 3.5 %).The developed model allows a reduction of the scope of preclinical experimental investigations, prediction of the behavior of the fixator during the postoperative fracture treatment period and creation of preconditions for subsequent structural optimization of the external fixator.

In this paper, an analytical calculation of load on bridge crane carts winch wheel loads was performed based on which FEM analysis and topological wheel optimization were performed. After the calculation, a standard wheel diameter was adopted. During FEM analysis in the CAD system, SolidWorks noted that certain surface areas had extremely low stress values, which was the main reason for the topological optimization of the wheel. The topological optimization of the geometric 3D model of the wheel is made in the CAESS ProTOp software, resulting in optimized 3D geometric wheel model. These models offer a number of advantages, such as saving materials to produce, reducing their own weight, balance stress conditions and easy customization model optimized technologies of additive manufacturing. This model of analysis and optimization was performed on the laboratory model of the bridge crane and it is applicable to all types of cranes.

The purpose of a car jack is lifting the car and maintaining it at a certain height during different repairs. This paper focuses on the design of car jack, which belongs to the basic equipment of cars. Cars jacks are used mainly for changing tires and small repairs of a car. The aim of this paper was to create a parametric CAD model of a car jack and carry out numerical structural analysis of the car jack using the created parametric CAD model. The development of the parametric CAD model and structural analysis was performed using the CATIA V5 system. This paper describes the modern way of creating more complex mechanisms, which support quick modification of its parameters, and thus the entire design. The whole model of the car jack was parametrized. The stresses obtained by finite element method (FEM) analysis were confirmed with the analytical calculation in characteristic parts of the design, with some exceptions. At the end of the paper, an analysis of the obtained results was performed, on the basis of which specified conclusions were made.

Difference between industrial designer and product designer is not precisely defined. There is a lot of discussions and misunderstandings about these two professions. What is the job of industrial designer and what is the job of product designer? This question if often asked from people, which want to hire someone to design a new product for them. Through this research, same real-life design contest is given to group of students from Faculty of Mechanical Engineering, Department of Mechanical Design, at Industrial design course and to group of students from Academy of Fine Arts, Department of Product Design as product design project. Goal of the contest was to design an upholstered chair for indoor use with a modern and refined style. Goal of this research was to find some unique characteristic of designs from industrial designers and product designers. Resulted designs were evaluated analysing the fulfilment of the requirements criteria defined by contest and analysing additional criteria, which is important for new product design. Analysing the resulted designs some important conclusions are made. Most important conclusion is that industrial designer can be product designer but product designer cannot be industrial designer. For product design, engineering knowledge is not necessary, but for industrial design, it is most important.

Integrated intelligent CAD systems (IICAD) can be developed for different purposes. The objective of this article is to emphasize the advantages of the use of IICAD systems in comparison with the classic systems. The article shows a structure of one such developed system, namely the IICADv system. This system is used for automatization of activities undertaken during the realization of certain phases of the process of designing of shafts, especially the synthesis phase. The development of a module for computation of the shaft and integration of the entire system was performed in the C# programming language, while shaping of the shaft was performed in the CATIA system. The interlinking was performed thanks to previously modelled basic 3D models. In such way, utilizing the advanced IICADv system, the computation and shaping of the shaft is done almost instantly. The results of the use of the IICADv systems are generated final 3D models of the shaft, ready for use by numerous other applications.

The scope of research of this paper is designing, modelling and analysis of tools for cold forging of rolling bodies of roller bearings. Basic principles of metal processing using plastic deformation are presented for better understanding of the forging process. Geometric tool modelling required knowledge of interconnections between individual tool elements, and their role in the forging process. The paper presents geometric and mathematical modelling of tools, and simulations of their operation. This presented a complete overview of movements of individual tool elements, which improved its functionality. In order to minimise errors in tool making and its stability, stress analysis and material yield at forging were taken into consideration.

The cranes are now not replaceable mode of transport of materials and finished products both in production halls and in the open space. This paper made the whole analytical calculation of double girder bridge cranes to be used in laboratories exclusively for testing, determined by the maximum bending stress and deflection of the main girder. After calculating the dimensions, we created a model cranes in software CATIA V5. The same model was subjected to FEM analysis of the same name software. At the end of the paper comparison has been done. The objective of the calculation and analysis of the model was to develop a model crane and to serve for the next tests. Dimensions of the crane are given according to the laboratory where it will be located.

This paper describes the stress analysis of devices for external fixation based on composite materials and stainless steel, which was performed numerically in the software CATIA V5 and which results are verified experimentally. The aim of this paper is to explore the possibility of introducing composite materials in the construction of the connecting rod fixator comparing values of displacement, principal and von Mises stresses at characteristic points structure. We investigated constructional performance of external fixator with a connecting rod formed from composite materials, and other components of external fixator formed from stainless steel. CAD model of external fixator was made in the software system CATIA V5. Also, in the same software was conducted structural analysis of external fixator under axial compression, and results were compared with experimental test. Finally, in concluding observations, we noted some advantages and disadvantages of the application of composite materials at the external fixator.

The proven safe operation and the high availability of aerial ropeways is mainly thanks to their design. This is based on the manufacturer’s extensive experience as well as the strict application of the relevant rules and norms. In that regard, this paper describes an analysis of the haulage ropes on ropeways in case of accidental loads. In solving this problem, analyzed ropeway system with sufficient accuracy was modeled as a system with three degrees of freedom. For solving differential equations we have used the software “Wolfram Mathematica”. At the end of the paper, we discuss the results of the dynamic forces in the haulage ropes in a certain time interval, and the results of the safety factors which in this case are sufficient to ensure reliable operation of the system.