A numerical based design approach for automotive space frame structures considering their crash behaviour

摘要

Computer Aided Engineering techniques (CAE) are extensively used for designing car body structures. However, their success depends on the accuracy of input data used in the analysis. This poses restrictions on their use in concept design phase of the car body, as the accuracy and availability of input data is limited during this phase. This thesis develops a knowledge-based design approach to address these challenges. It also demonstrates the application of this approach for conceptual design of a profile based car body structure designed for crashworthiness.The knowledgebase for the presented design approach is developed by analysing the results from two sets of numerical experiments carried out during this work. The first set of finite element (FE) simulations is performed on two benchmark vehicles constructed using the classical construction concept for various crash scenarios. The behavioural trends observed from this set of simulations are used as basis for defining crash design targets for a new profile based car body structure. The second set of FE simulations is performed on the components of a profile based car body structure. The data obtained from this set of simulations are used to evaluate different analytical methods available for predicting the behaviour of car body components under crash loads. Regression analysis is performed on these simulation results to formulate equations that can be used for designing components of the new car body structure. Application of this design approach is demonstrated and validated by generating a concept design of front end of a micro-sized electric vehicle.