Fatigue analysis of engine brackets subjected to road induced loads

Abstract: In this master thesis, methods for fatigue analysis of front engine brackets subjected to road induced gravity loads (g-loads) are studied. The objective of the thesis is to investigate the possibility to improve simulation and test analysis for the components. The powertrain is modeled with varying degrees of complexity and the different models are compared to each other and to Scania's models for analysis of the engine suspension. The analysis begins with g-loads and proceeds with time-dependent loads. It is investigated how simulated strains in the cylinder block correspond to measured strains from the test track at Scania. Finally, it is investigated how component tests corresponds to actual loads by comparing the results. The results from the first part of the thesis indicate that worst load case is loading in the negative z -direction and the model of the powertrain with isolators modelled as spring elements is the best for g-loads lower than -3g and the model is sufficient for loads lower than -8g. The results from the second part of the thesis indicate that the simulated strains generally correspond to the measured strains, but with a slight difference in strain amplitude.