In the automotive industry, crash analysis plays an important role in the virtual product development of the design of the car body. The minimization of weight and competing requirements from several load cases have to be adjusted as optimal as possible. Consequently, high safety limits cannot be kept while maintaining all requirements. Therefore, the assurance of robustness of the optimized design against unavoidable scatters of crash test constraints, production constraints and material constraints in preferably early stages of product development becomes more and more important. Therefore, numerical robustness analysis is recommended as method of stochastic analysis in virtual product development.
Robustness analysis is primarily carried out to determine the variation range of significant response variables and their evaluation by using definitions of system robustness due to the unavoidable scatter of design parameters. Robustness analysis of structural crash load cases has high demands for the methods of stochastic analysis, statistical measures of determination and correlation as well as the efficiency of post processing. Reasons for this are the complexity of modelling, long calculation times, high non-linearities and the influences of numerical noise.
In this paper using the application of crashworthiness of car under insurance load cases robustness analysis will be illustrated. Since the deterministic analysis couldn't imitate the realistic behaviour of the car in the virtual product development, robustness analysis is used for the numerical assurance of car bodies against scatters of material, sheet thickness and test constraints. The Stochastic and structural analyses are performed with the optiSLang, and LS-DYNA software packages.