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This article presents a new approach aiming to reduce gear vibration and weight by modifying its body structure. The primary objective was to reduce vibration and noise emission of spur gears. For this purpose, a solid gear body was replaced by a lattice structure, which was expected to raise the torsional compliance of the body. The lattice structure was configured and optimized by a FE-based topology optimization software. For experimental purposes, the optimized gear was produced from Titanium alloy Ti-6Al-4V ELI using Selective Laser Melting technique. In the tests, the sound pressure of various running gear pairs was measured in order to estimate and compare the properties of a solid gear, of a lattice gear, and of a lattice gear, filled with polymer to increase the structural damping. It was experimentally confirmed that the cellular lattice structure of a gear body and addition of a polymer matrix may significantly reduce the vibration. [ABSTRACT FROM AUTHOR]

Effective method for analyzing of the terrain vehicle suspension performance is presented. The key objective of this approach is to make quick analyses of the vehicle suspension system performance. The vehicle is simplified by mathematical modeling of a quarter of it and equations of motion are solved by using Matlab software. To verify the reliability of the proposed method a comparison with one of the simply commercial software is done. The usefulness of the proposed method on the real terrain vehicle is presented in order to analyze the sensitivity of the several suspension parameters such as spring stiffness coefficient, damping coefficient, tire stiffness coefficient, sprung and un-sprung masses. The sensitivity of the suspension parameters is determined by considering of the vehicle body acceleration, vertical tire force and suspension travel that directly influences on the driving comfort and driving safety. [ABSTRACT FROM AUTHOR]

This paper presents a simple and effective approach to improve engine performance of a racing car with special requirements. Attention is focused on optimal design of the intake system, using a gradient-based approximation method of mathematical programming. Since optimization relies on accurate numerical analysis of engine processes, the sub-models and parameters needed in the analysis software are carefully determined by experiment. Subsequently, the influence of different design parameters of intake and exhaust systems on engine performance is investigated numerically. The most influencing parameters are selected to be the design variables in the optimization process. In order to improve engine power at several engine speeds, two different forms of the optimal design problem are proposed, solved, and compared as a means to identify the most appropriate one. Since the analysis software is a black-box program, the optimization procedure is implemented by employing the optimization software as a master (driver) program while the analysis software acts as the slave program. The data exchange between these programs is established by XML data files and suitable wrapper programs. The results obtained confirm the usefulness of the approach presented. [ABSTRACT FROM AUTHOR]

The paper describes the influence of contact area on the service life of dynamically loaded gears with a crack in a tooth root. Numerical results obtained with the finite element method using the program package BERSAFE are compared with the experimental results obtained on the universal testing machine INSTRON 1255. Numerical and experimental results are in good agreement. The analysis shows that the contact area directly influences the speed and direction of the crack propagation and the service life of the gear with a crack in a tooth root. [ABSTRACT FROM AUTHOR]