Validation of a fabric model for crash simulations of composite structures

The paper describes recent progress in DLR's research on the analysis of the crash behaviour of composite energy absorbing structures. Latest developments and verifications of a material model to simulate the crash behaviour of structures made of composite fabric plies with the explicit FE-code PAM-CRASH will be presented. Basic material properties of two different fabric materials are summarised which are used to generate the input data for the new fabric material model. With this material model verification analyses are performed starting on single element and specimen level which showed a good agreement to the corresponding test results. In a final step, simulations on hybrid trapezoidal beams which were crash tested under complex loading conditions are presented. In this study two of the beams were tested with a partial overlap of the specimen and impactors of different shapes, while a third one was tested on an inclined surface of 20° in the longitudinal direction. The forth test was performed on a specimen with two circular holes in the web area to investigate the evolution of damage and failure. In general, a very good correlation between the test results and the simulations with the improved fabric material model was found