Explicit dynamics finite element analysis of energy absorption characteristics of thin-walled UltraSTEEL columns

UltraSTEEL material has been reported to have higher yield and ultimate strengths than plain mild steel under quasi-static loads. This project aims to study the energy absorption characteristics of UltraSTEEL thin-walled structures when subjected to axial impact loads. The numerical modelling starts from duplicating the UltraSTEEL dimpling process and defining the resultant material properties by taking strain hardening and strain rate sensitivity into consideration. Features including element type, mesh density, symmetric boundary conditions and imperfections are then studied. The responses of 1mm gauge plain and UltraSTEEL columns to the same impact load are compared by conducting explicit dynamics finite element simulations. Comparing to the plain columns, the effect of gauge on the UltraSTEEL columns’ failure mode and specific energy absorption (SEA) are analysed through a parametric study.