Methodology for Predicting the Structural Response of RPC-Filled Steel Tubular Columns under Blast Loading

Reactive powder concrete-filled steel tube (RPC-FST) is a critical supporting component of large-span, high-rise, and heavy-load structures. The collapse of RPC-FST may occur under explosive load. Therefore, investigation of the dynamic response is essential for understanding the mechanisms of collapse. In this article, the numerical simulation of reactive powder concrete (RPC) adopted the modified Holmquist-Johnson-Cook (HJC) model and the modified Karagozian and Case (K&C) model. The dynamic response of RPC-FST columns under explosive load is analyzed based on arbitrary Lagrange-Euler (ALE) method. The proposed model is verified by experimental results. Results show that the modified HJC model and modified K&C model can be applied to simulate the dynamic response of RPC-FST columns under explosive load. As compared with the modified HJC model, the modified K&C model has more accurate results. This phenomenon mainly accounts for the lack of ultimate strain of RPC (EFMIN). To analyze the reliability sensitivity of RPC-FST, an efficient probability analysis method is proposed based on the Kriging model and Monte Carlo simulation (MCS). The proposed method considers five nonlinear factors, including weight and distance of TNT, height and section diameter of RPC-FST, and steel tube thickness. Finally, the sensitivity of each factor is evaluated. Results show that TNT weight greatly influences the reliability of the RPC-FST, followed by TNT distance, RPC-FST height, RPC-FST section diameter, and steel tube thickness. In addition, the RPC-FST dynamic response analysis method based on the Kriging model and MCS can improve the calculation efficiency by more than 200 times compared with the ALE method.