Numerical modelling of ECC encased concrete-steel composite columns with high strength materials

A good numerical model is a feasible alternative to costly experiments and a handy tool for predicting the response and behaviour of structural elements under wide range of scenarios. Modelling of encased composite columns with high strength materials can be challenging especially for the post-peak region due to crushing and sudden expansion of HSC, local buckling of embedded steel section and interface bond failure between different components. This study present a detailed 3D nonlinear modelling procedure for engineered cementitious composites (ECC) confined fully encased (ECC-FEC) and partially encased (ECC-PEC) composite columns with high strength materials. The commercial finite element modelling (FEM) software ABAQUS was used to develop the numerical model. ECC and HSC materials were modelled using concrete damaged plasticity (CDP) model and their stress-strain responses were described using simplified constitutive models. Numerical models were validated against test results and good agreement was found. The model introduced in this study is able to predict the ultimate capacity, load-deformation response and failure behaviour of ECC-FEC and ECC-PEC columns. A parametric study using validated models by extending the material strengths was also included in this study.