Dynamic behaviour of Advanced High Strength Steels used in the automobile structures

Abstract
The growing use of high strength steels in the automotive industry, to improve the crashworthiness and the light-weighting of the car body, requires the knowledge of their behaviour over a large range of strain-rates. The accuracy of the results in medium and high strain-rate tests is often strongly influenced by the experimental techniques used for the mechanical characterization of materials. Moreover, the precision of the constitutive law in reproducing the actual behaviour of the materials has important consequences in the correctness of design and assessment of car body structures subjected to impact loading. The paper presents the experimental techniques used to carry out dynamic tensile tests on thin sheet specimens. The research includes several Advanced High Strength Steels as Dual-Phase steels, TRansformation Induced Plasticity steels, etc. The tests have been carried out in the three strain-rate regimes (1–5, 10–50 and 500 s⁻¹). The comparison of the dynamic stress-strain curves of three DP steels is presented and discussed.