Simulation model for ultra-high strength concrete filled composite column under static loads

![CDATA[Previous experimental research at National University of Singapore on ultra-high strength concrete (UHSC) filled composite columns exhibits that the brittleness of UHSC of compressive strength up to 200MPa can be overcome due to the passively confinement supplied by steel tube. Therefore, how to consider the confinement effect reasonably is the key issue of simulating the behavior of UHSC filled composite column under static loads. In this paper, based on existing stress-strain relation for normal strength concrete, a UHSC stress-strain relation model is proposed, which is confinement-dependent and fits for the Concrete Damaged Plasticity Model (CDPM) in ABAQUS. The suggested stress-strain relation model is adopted to establish finite element analysis models of UHSC filled composite circular columns subjected to vertical load or bending. The FEA models are validated to be reasonable compared with existing experimental results, and the limitation of the models which leads to inaccurate predicted results is also discussed in the end of the paper. Based on the FEA models, the mechanical performance analysis and systematic parameter analysis can be carried out to UHSC filled composite columns in the oncoming research.]]