Deformation and failure properties of cylindrical battery packs under quasi-static and dynamic indentations

Battery packs, serving as the primary power source in electric vehicles, are essential components; however, their failure behavior under common side collisions-particularly those involving localized dynamic loads and repeated impacts-remains insufficiently understood. This paper investigates the deformation and failure behavior of two battery packs configured in triangular and checkerboard arrangements (T-battery and C-battery packs) through quasi-static indentation, dynamic impact, and repetitive impact experiments. The results indicate that under quasi-static indentation, T-battery packs deform in a "triangular mode", while C-battery packs deform in a "rectangular mode", resulting in a more generous failure displacement for C-battery packs. With the increase of impact velocity, the battery pack exhibits a pronounced strain rate effect, with a progressive transition from extrusion failure to brittle fracture. This transition is characterized by bending fractures in T-battery packs and internal jellyroll cracking in C-battery packs. Additionally, repeated impact experiments reveal that T-battery packs demonstrate superior impact resistance compared to C-battery packs. A power-law relationship between single impact energy and the number of impacts was established, providing a means to predict the failure energy threshold for battery packs.