Unified parametric car model A simplified model for frontal crash safety Abstract 15jun12

In addressing crash protection of car front ends, three different energy levels are encountered in the form of pedestrian crashes, low and high speed crashes against obstacles and other vehicles. The aim is to approach vehicle front design problem as three separate formulations at the initial phase of the product development process instead of one complex model. Therefore three highly parametric complex models are established to identify the variables with high impact on the self and partner protection as well as pedestrian safety. In the second stage, the three simplified models are merged together into one LS-Dyna model to run global multi-objective optimizations using results obtained from the previous approaches as Design Space and constraints for different requirements of front-end safety. The following three models will be evaluated for simplification, robustness and validation possible for specific goals. Model 1: Pedestrian Safety The role of shape and the stiffness of the front end structures on the injuries of pedestrians (6yr old child to 95%-ile male adult) are covered within this research. Madymo pedestrian models are used by Dyna/Madymo coupling. Model 2: Car to Car To improve the overall crash behaviour in a car to car crash the topology of the interacting structures of different vehicle types will be optimized. Model 3: Car to obstacle The shape and structure of a crashbox is optimized to improve the behaviour in terms of energy absorption to weight ratio. The validation is being covered with a FE Model of Toyota Yaris from NCAC. This paper shall give an overview about the simplifications and the process of verification and validation of the three model approaches leading to a single effective simplified vehicle-front model. A detailed description of the implicit parametric CAD model will be presented along with different interfaces and tools to create an automated optimisation loop, effectively leading to a comprehensive Design Methodology.