Numeriacl Simulation Of Metallic Circular Tube With Aluminium Foam Filler Under Axial Impact Loading

Thin-walled metallic circular tubes with aluminum foam filler was widely used in improving structure crashworthiness, energy absorption and reducing structure weight. By using the finite element software ANSYS/LS-DYNA, the single thin-wall metallic circular tube and double thin-wall metallic circular tube with foam aluminum filler under axial impact loading are researched, and the deformation process and energy absorption of two kinds of composite structures are analysised. On the basis of the previous experimental data, the finite element model has been established. The numerical results are good agreement with the experimental results. So the finite element models in this paper are right. According to the radial displacement distribution curve, the von misses stress and the energy absorption curves of each composite structure, the model geometry dimension and the densities of aluminum foam impact upon the energy absorption of the composite structure. Under the same impact conditions, the absorbing energy curves of the single circular tube composite structure and double circular tube composite structure are compared at the same time, and the advantages and disadvantages of two kinds of composite structures are given. The main conclusions in this paper are as follows:1. Under axial impact loading, the amount of absorbing energy of thin-walled metallic circular with aluminum foam filler is greatly bigger than that of aluminum foam or metallic tubes alone.2. The longer the length of the model, the smaller the densities of aluminum foam filler and the thinner the thickness of metallic tube, the bigger the axial displacement of two kinds of structures when they are compressed. The thicker the thin-walled metallic tube, the bigger the von misses stress. But the different length of the composite structure and densities of the aluminum foam have little effect on the mean stress of two kinds of structures. Increasing the thickness of the thin-wall metallic tube or the density of aluminum foam, the ability of absorption energy of the composite structures is improved, but the length of composite structure has little effect on that.3. Under the same impact quality and impact velocity, because of the interaction between double tubes and foam aluminum, the maximum radial displacement of single circular tube composite structure is bigger than that of double circular tube composite structure, but the von misses stress is smaller. Because of aluminum foam between internal and external tube is fully compressed, the amount of absorbing energy of double circular tube composite structure is bigger than single circular tube composite structure in the same time. Numerical result shows that aluminum foam compressed degree in composite structure has big impact on absorbing energy of the composite structure.