Dynamic Response Analysis of Infilled RC Frames with Openings Under Instantaneous Column Removal Scenarios

In order to further explore the role of infill walls in the progressive collapse resistance of reinforced concrete (RC) spatial frames, based on ANSYS/LS-DYNA finite element analysis software, the refined numerical models of pure RC spatial frames and infilled RC spatial frames were constructed, respectively. By comparing it with the experimental results, the validity and accuracy of the model are verified. Subsequently, the effects of column removal devices and infill wall openings on the progressive collapse resistance of RC spatial frames were studied. The results show that the residual displacement of the model with a complete column removal device is 238.1% higher than that of the model with an incomplete column removal device, and the stiffness is reduced by 68.8%. The results obtained by an incomplete column removal device are often unsafe. The open-hole infill wall will form a diagonal strut in the corresponding area. The strength of the strut near the fixed end has the most significant effect on the structural stiffness after the column is removed and plays a controlling role. The reduction in the effective area of the strut reduces the strength of the strut and weakens the structural stiffness. When the opening is arranged in the mid-span position, the structural stiffness decreases more significantly.