Vývoj metodiky více - osého dynamického testování materiálů pro automobilové konstrukční skupiny

Abstract

The aim of the dissertation is to create a comprehensive methodology for testing the automotive front axle construction group - the weight. The proposed methodology will be applied primarily in the selection of a suitable technical solution and material for this highly stressed element of the axle. The theoretical part describes the current state of testing methods for front axle elements and the finite element method (FEM) as a tool for creating a 3D model and simulating force analysis. At the same time, factors that significantly influence or limit the choice of material are discussed here. These are, for example, specific weight, chemical composition, mechanical properties, fatigue limit, anisotropy factor and others. The goal of the work is the planned change of the input material of the block made of ductile iron to a high-strength aluminum alloy. As part of the experiment, the original hypothesis of the possibility of using an aluminum alloy was confirmed by optical measurement of deformation on a multiaxis dynamic testing device by the digital image correlation (DIC) method. Basic driving limit states, braking and cornering were compiled and defined. The measured outputs were compared with the finite element method (FEM) calculations. The ingot for the experiment was made for a specific SCX3 prototype vehicle from EN AW-7075 T6 aluminum alloy. The results of the measured and calculated data were compared with the proof yield strength and fatigue strength. Furthermore, a suitable fatigue criterion was used, which can be applied for multiaxial cyclic loading of an automotive component. The fatigue criterion modified and refined the results of the prediction.