Abstract
For the vehicle frontal crash development, matching the stiffness of the front end structures reasonably, i.e., impact energy management, can effectively improve the safety of vehicle. A multi-condition analytical model for vehicle frontal crash is construct by three dimensional decomposition theory. In the analytical model, the spring is used to express the equivalent stiffness of the local energy absorption space at the front-end structure. Then based on the analytical model, the dynamic responses and evaluation indexes of the vehicle in MPDB and SOB conditions are derived with input of crash pulse decomposition scheme. Comparing the actual vehicle crash data and the finite element simulation results with the calculation results of the proposed solution method, the error is less than 15%, which verifies validity of the modeling and the accuracy of the solution. Finally, based on the solution method in the MPDB and the SOB conditions, the sensitivities of crash pulse decomposition scheme to evaluation indexes are analyzed to obtain qualitative rules which guide crash energy management. This research reveals the energy absorption principle of front-end structure during the frontal impact process, and provides an effective tool to manage the vehicle crash energy considering multi-condition.
Variable Stiffness Design and Multiobjective Crashworthiness Optimization for Collision Post of Subway Cab Cars
