Key Technology Research On Fatigue Life Prediction Of EV Battery Packs

With China rapid economic development in recent decades, the number of cars increasing, automobile exhaust emissions into the atmosphere has become one of the major pollution sources of the air, However, travelling by car is a necessity and an important part of cultural life, Which determines the Green new energy vehicles will gradually become the the main trend research and development around the world. Batteries are the key parts of new energy vehicles. Therefore, design a stored energy, long life, reliability, high power batteries have become the focus of the study.Battery pack on structural fatigue life is an important issue in this article, First of all, briefly reviewed the present situation of research in the field both at home and abroad, Includes theoretical aspects of research and innovation. Battery pack structure primary connections weld together. Welded joints are the most susceptible to fatigue failure of weak links. Most fatigue failure often happen here. It is not theoretically affect the fatigue of various complicated factors, Summarized into a unified mathematical model or physical model study. Therefore, both at home and abroad on fatigue research is mainly done by experiment, fatigue research on welded structure even more so. However, fatigue testing without physical prototyping, through physical prototype testing cycle is long and costly, especially for complex products, subjected to complex loads on the test bench trials, currently being realized is difficult. Therefore, based on numerical simulation technology, battery pack for scientific prediction of fatigue life of welded structures, and then conducting a comparative analysis of different scenarios.BP-1battery pack for the study, based on the basic theory of finite element theory, Hyper Works11.0software as a tool, the establishment of finite element model of BP-1battery pack, apply the ANSYS Solver, solving static strength analysis of the battery pack. Then based on strain-load time history data collected using rain-flow counting and frequency extrapolation make statistics to obtain the actual load spectrum.Combining research results made by our predecessors, on the fatigue mechanism analysis of metal welding, elaborated on the factors that influence fatigue life and fatigue failure of the whole process. Based on virtual fatigue test technology, gain strength on the basis of data of the battery pack, using United States structures in the ASME2007stress method and master s-n curve of welding structure based on fatigue life prediction of weld, reference Miner linear fatigue damage cumulative theory on fatigue life prediction of weld in the battery pack. Finally, using nominal stress method to calculation of cumulative damage from new, which gets the value object of study cumulative damage to battery pack important structural reliability design of the theoretical value and practical significance.