During the past two decades explicit Finite Element crashworthiness codes have become an indispensable tool for the design of crash and passenger safety systems. These codes have proven remarkably reliable for the prediction of ductile metal structures that deform plastically; however, they are not reliable for joining systems and materials such as high strength steels, plastics and low ductility lightweight materials all of which are liable to fracture during the crash event. In order to improve crash failure prediction of materials and joining systems the CEC has recently funded a three year European research project dedicated to this topic. Specifically the project concerned Aluminium, Magnesium, High Strength Steels, Plastics and two primary joining techniques; namely spotwelds and weldlines. Numerous new developments were undertaken including improved failure laws,

Abstract. Split Hopkinson Tension Bar (SHTB) experiments can be used to test the material behavior with high strain rates in tension loading. The influence of the specimen mounting and the specimen design on the test results was investigated. Three mounting methods were tested. The best signal is achieve using a mounting based on form fit. The three tested specimen designs all lead to a valid fracture behavior, but result in a different local strain rate.

Titanium foams of relative density in the range 0.35 -0.50 are tested in quasi-static compression, tension and shear. The response is ductile in compression but brittle, and weaker, in shear and tension. Virtual foam microstructures are generated by an algorithm based on Voronoi tessellation of three-dimensional space, capable of reproducing the measured size distribution of the pores in the foam. Finite Element (FE) simulations are conducted to explore the mechanical response of the material, by analysing the elasto-plastic response of a statistical volume element (SVE). The simulations correctly predict the ductile compressive response and its dependence on relative density.

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