서강대학교

초록/요약

In these days, the performance of the currently developing car continues to increase, and the paradigm of the power source is shifting from internal-combustion to electric power. In the development phase of the vehicle, changes in power system include the main power unit and the parts, chassis layout, fuel systems, etc., and it is necessary to develop a lay-out analysis associated therewith. Especially, most batteries are mounted at the bottom near the rear-axle and rear-wheel. However complementary rigid design elements of the random chipping phenomenon that can occur in the underbody part have not been established. In addition, it has been developed by borrowing the lay-out of complementary measures without the predecessor vehicle for this purpose. Therefore, there could be a high risk due to random stone chipping that may occur on the underside of the vehicle, resulting in loss of vehicle functionality or accidents. The mathematical modeling and statistical probability application of chipping phenomena as well as its cause by tire slip and power transfer efficiency defines the critical zone of the vehicle underbody that could cause damage to the underbody parts, and then this approach enables prior prediction of the impact area. Using this method, it is possible to analyze factors for analyzing design rigid elements of underbody and enhancing safety during the component design phase. In this paper, the robustness element for chipping phenomena is defined as the rigid design element of underbody that enables the vehicle to secure bend stiffness. A rigid design with minimum deformation for external impact can be also proposed by introducing rib structures. Therefore, rigid factors and variables of ribs were considered through a finite element analysis based on the test plan. The impact visualization test equipment was constructed to verify the robustness design. In this thesis, the impact deformation and robustness of underbody parts were verified by simulating a similar situation to the impact phenomenon by stone chipping using actual impact visualization test equipment. Through this process, it is possible to propose the rigid design of underbody parts that can protect the battery system of electric vehicle and to present alternatives to experimental techniques. Moreover, it could reduce the cost of testing and the development period by presenting design guidelines for external impacts in the future development of vehicles and components.