NUMERICAL STUDY ON THE POST-IMPACT MECHANICAL PROPERTIES OF CONCRETE-FILLED HIGH-STRENGTH STEEL TUBES

To analyze the post-impact mechanical properties of concrete-filled high-strength steel tubes, a numerical model for the residual axial compression resistance of concrete-filled high-strength steel tubes under low-speed lateral impact and axial compression is established in this paper. The model takes into account the material strain rate effects of high-strength steel and concrete, as well as the transfer of results between the dynamic and static analysis procedures. The feasibility of the model is verified using the existing low-speed lateral impact and static loading test results of concrete-filled high-strength steel tubes. The established finite element model is used to compare and analyze the influence of failure mode, local damage and mid-span deflection of post-impact concrete-filled high-strength steel tubes after lateral impact and static lateral loading on its residual axial compressive resistance, elaborating the key factors affecting its residual axial compression resistance. A simplified calculation model for the residual axial compression resistance is established based on the analysis.