Development of a strain-rate dependent progressive damage model for crash analysis of composite laminates

Abstract
The present study aims at development of a macro-mechanical progressive dynamic damage model for evaluating the crash behavior of composite laminates under intermediate strain rate and implementation in explicit dynamic finite element code LS-DYNA. Construction of this model is including two important attributes of their mechanical behavior namely strain-rate dependency and progressive failure behavior which make it suitable for dynamic simulations. To create a rate dependent physical model as a powerful device, mechanical properties are fully characterized by performing tension and compression tests on 0°, 90° and ± 45° specimens at strain rates range from 0.001–100 s⁻¹ using a high-speed servo-hydraulic tester. The experimental results show the rate dependency in the properties of all test specimens. Based on the results obtained, the empirical material models are proposed in terms of strain rate. Also, stress-based macro-mechanical dynamic failure criteria including different failure modes and corresponding material property degradation rules are established to model the progressive failure behavior. The developed models are programmed as a user defined subroutine in the non-linear code LS-DYNA. Experimental results on the quasi-isotropic specimens under high stroke-rate are used to validate the model's prediction. The model shows a good agreement with the experimental results.

Note to the reader: On page 1263, the name of the author M.O. Jamal has been corrected in M.J. Omidi on January 26, 2010