Reliability modeling and evaluation method of IMA under dynamic reconfiguration

This article studies the dynamic response characteristics of cylindrical lithium-ion batteries under large deformation based on the membrane factor method to improve the safety performance of batteries under radial dynamic impacting. Firstly, the battery was simplified to a sandwich beam consisting of a casing and an inner core. The plastic yield criterion and membrane factor of the battery cross-section were established based on tensile yield strengths. The membrane factor was introduced into the motion equation to solve the dynamic response under large deformation. Furthermore, the mechanical properties of the battery components were determined based on tensile and compression tests. Then the finite element (FE) model of the battery was developed. It has been shown that the theoretical and FE results of the displacement and velocity responses of the battery were in good agreement. The larger the initial velocity of the battery under impact loading, the stranger the axial force effect on the dynamic response. The maximum deflection of the battery increases approximately linearly with the initial velocity, and the actual response time shows saturation. The maximum deflection of the battery increases with the decrease of the ratio of casing yield strength to core yield strength. The effect of yield strength is significant when the battery casing is thin. The maximum deflection of the battery decreases with the increase of casing thickness. Under a high yield strength ratio, the effect of casing thickness is significant. The research can provide technical support for failure prediction and structural safety design of batteries.