Axial crushing of circular thin-walled specimens made of CFRP using progressive failure model (MAT54) in LS-Dyna

This research focuses on calibrating the MAT54 (ENHANCED_COMPOSITE_DAMAGE) material card in LS-Dyna for simulating axial crushing of circular thin-walled specimens made of CFRP. An IM7/8552 composite specimen showing the layup sequence of [902/±452/02]2 was simulated in LS-Dyna using shell elements. Following a trial-and-error-based method, the physical and non-physical input material parameters of MAT54 were calibrated. The calibrated input parameters included material strengths, failure strains, softening factors, and damping coefficient. The results of this study showed the applicability of the use of the physical material inputs from material characterization tests (e.g., tensile, in-plane shear, and compression) while showing the necessity of more in-depth calibration processes for the non-physical material inputs (e.g., viscous damping coefficient, crashfront reduction algorithm, etc.). The initial model predicted the specific energy absorption with an error of −57.95 % and this was improved by the calibration process to an error equal to −1.49 % for the final model. Now validated, the model will be used in the future to simulate impact into composite vehicle armor.