Experimental and numerical study in axial crushing of thin walled sections made of high-strength steels

Abstract
The interest in dynamic plasticity has greatly increased in recent years driven by avances in computational power and by industrial needs. The knowledge of material properties is required as well as adequate constitutive equations capable of describing material behaviour. Results are presented in this study for the tensile testing of Dual-Phase and TRIP (Transformation Induced Plasticity) steels at different strain rates. The test results were used to obtain Cowper-Symonds coefficients with the intent of describing strain rate sensitivity of material properties. The crashworthiness of thin walled sections made of Dual-Phase and TRIP steels was subsequently investigated. Crush tests were performed at different speeds on top-hat and hexagonal tubes. The experimental results were compared with numerical simulations obtained with LS-DYNA software. The influence of the material models in the accuracy of simulations was examined.