Estimation of the Strain Rate Hardening of Aluminium Using an Inverse Method and Blast Loading

Abstract

The dynamic behaviour of structures under blast wave loading is increasingly studied due to the rising risks of intentional and accidental explosions and the development of new protective technologies and methods. To ensure the efficiency of these protective measures, the identification of the material behaviour under blast loading is of utmost importance. This paper investigates the feasibility of the identification of the strain rate hardening of aluminium using an inverse method and blast loads. The results of a series of tests on aluminium plates loaded by means of an Explosive Driven Shock Tube are reported. A numerical study is performed to develop a model that is both in concordance with the experimental measurements and suitable for loop implementation. The 3D high-speed full-field measurements and finite element simulations are used to accurately assess the dynamic response of the plates. The identification is based on the Levenberg-Marquardt formulation for damped least-squares solution. The approach is virtually validated and its sensitivity to noise is studied using virtual measurements from finite element calculations. Then, experimental data are used for the identification. The results obtained are within the range of expected values based on literature.