PENG Zhiming, CHEN Zhongfan, XU Zhifeng, HUANG Yuhao, LUO Yi
In order to promote the development of cold-formed thin-walled steel building structure system and improve its assembly ratio, three dry assembly forms of connection between the flanges and webs of the walls were proposed. To study the seismic behavior of the composite walls, three different prefabricated cold-formed thin-walled steel-foam concrete composite wall specimens and one cast-in-place wall specimen were tested under low-cycle reciprocating load. The failure mode, bearing capacity, lateral stiffness, energy dissipation and ductility of specimens were analyzed. The reliability of the three types of dry connection and the differences in seismic performance of the walls with different assembly forms were studied. The results show that the failure of the wall is mainly concentrated in the web pier, the wall panels between the columns and the foam concrete filled inside appear crossed oblique cracks, the horizontal braces are subjected to local buckling, and only a few horizontal and vertical cracks appear at the bottom of the flanges of the wall pier. The three dry connections are safe and reliable, and the components fail before the joint. Compared with the cast-in-place counterpart, the bearing capacity and initial stiffness of the assembly specimens are lower, but the deformation and energy dissipation capabilities are higher. Compared with the web spliced wall, the peak load, initial stiffness and total energy dissipation of the tensile connection wall are increased by 36.5%, 15.0% and 12.5%, respectively, and the peak load and total energy dissipation of the L-joint wall are increased by 22.8% and 54.5%, respectively, the initial stiffness is reduced by 21.5%. Considering the seismic performance, transportation condition and construction difficulty of the three assembly forms comprehensively, the assembly form of L-shaped connector is preferred for engineering practice. Based on the principle of superposition, the lateral stiffness of the prefabricated composite wall was deduced, and the accuracy of the calculation method was verified.
