Collision Analysis Of Automotive Power Battery Pack With Lightweight Foam Aluminum Sandwich Panel Structure

With the aggravation of the energy crisis and the environmental pollution,electric vehicles have been paid much attention.However,due to the heavy weight of the battery(30%-40% of the total weight of an electric vehicle)and its pack,the weight of electric vehicles are generally large limiting the extension miles of the vehicle.Moreover,the battery pack which is used to fix and protect the battery is made of steel products.Such a design can further increase the vehicle load and reduce the endurance mileage.In this study,we aim to simplify the structure of the battery pack as well as replace part of its material with Aluminum alloy and Aluminum foam.By conducting finite element based collision simulation,we compared the collision performance of the battery pack with different structures and materials.Finally,we added such a pack of best collision performance into a full car model for the simulation of vehicle crash test.The side impact velocity can be as high as 20 km/h with the proposed structure and material of the battery pack.The results manifest that our design can provide references for the vehicle lightweight in the future.The procedure of this study is as follow.1)The compressive properties of materials are obtained by the compressive process with material testing machine.We also conduct the compression and bending experiment with the metal-foam aluminum-metal structural materials.2)The modelling of the battery pack is completed by CATIA(Dassault Systèmes,France).Two structures which are the single shell structure(Q235)and the sandwich shell(metal-foam aluminum-metal)structure of the pack are adopted for the comparison of the collision performance.For the sandwich shell design,we have three combinations of the materials which are aluminum alloy-4mm aluminum foam-aluminum alloy,aluminum alloy-8mm foam aluminum-aluminum alloy and Q235 steel-8mm foam aluminum-aluminum alloy,respectively.3)The deformation of the battery by the stress will cause accident leading fire and explosion.To validate the ability of protection of the battery pack,we conduct the compression test of lithium batteries and thus obtain the stress-strain curves of lithium batteries.4)The collision simulations with two structures of battery pack are completed in LS-DYNA.Then we compare the performance of the battery pack from the angles of the overall energy absorption,the overall displacement of the battery and the node displacement of the battery.5)The pack which performs best in the collision simulation is achieved and installed into a full-car model for the simulation of vehicle crash test.We find that such a structure(Q235 steel-8mm foam aluminum-aluminum alloy)lowers the total weight of the battery pack and has the best performance in the collision test.