Finite Element Modeling of Material Damage in Axially- Loaded Aluminum Tubes with Circular Hole Discontinuities

Finite element simulations of the axial crushing of extruded aluminum tube structures were conducted using LS-DYNA in order to investigate their load management and energy absorption characteristics. The structures under consideration were made from aluminum alloy 6063-T5 and contained dual centrally located circular hole discontinuities. The results of the finite element simulations are compared to the results of quasi-static experimental crush tests conducted on structures of similar nominal geometry and material properties. Due to the presence of significant cracking and splitting in the crushing modes observed during the experimental crush testing, a material model employing damage mechanics was assigned to the structure models. This material model was calibrated using the experimental crush testing results as well as tensile tests conducted using specimens extracted from the extrusion stock material. A good correlation was observed between the results of the quasi-static crushing experimental results and the results of the finite element simulations. The experimental peak buckling loads of the structures were predicted to within 10% by the finite element simulations.