Optimization Approach for Crashworthiness of Vehicles Based on Physically Defined Equivalent Static Loads for a new Topology

Abstract

Optimization Approach for Crashworthiness of Vehicles Based on Physically Defined Equivalent Static Loads for a new topology. The new method is based on principle energy considerations inspired from the current design process in modern automotive product development. The potential of the vehicle concept to absorb kinetic energy can be estimated at the very beginning of the design process by the free crash lengths in the different areas of the vehicle and estimates of average forces required in the specific parts of the car body at particular crash phases. Here it is important to determine appropriate force distributions and the corresponding load paths through the whole structure for all relevant crash load case. Depending on the vehicle type, a knowledge base is derived for the spatial and temporal distribution of force levels, which is then used in a temporal sequence of static topology optimizations. Standard topology optimization methods based on linear finite element methods are used in a time sequence where the loads are applied for certain time periods in special areas of the package assigned to the structure for different phases of the crash. For this it was necessary to derive distinct deformation phases characteristic for each crash load case and corresponding equivalent static loads, which reflect the actual transfer of loads through the structure.