冷弯薄壁型钢-结构防火一体板自攻螺钉连接性能试验研究OA北大核心CSTPCD

The shear test of self-tapping screw connection of cold-formed thin-walled steel-structure fireproof integrated board was carried out,and the monotonic tensile and low-cycle reciprocating loading tests of 35 typical specimens were completed,and the effects of structural fireproof integrated plate thickness,screw diameter,screw end distance and loading angle on their shear resistance were analyzed.The results show that the specimens with different loading angles and screw end distance showed different failure modes,mainly including tear failure at the end of the plate,pressure failure of the hole wall of the plate,and the failure of the plate to be pulled off,etc.,and the self-tapping screws of the specimens had different degrees of inclination during the failure.For test pieces with screws with a diameter of 4.8 mm and 5.5 mm respectively at the test end,the peak load and ductility coefficient of the specimen have no obvious correlation with the screw diameter,and the elastic stiffness increases significantly with the increase of the screw diameter.With the increase of screw end distance from 15 mm to 25 mm,the elastic stiffness of the specimen did not change significantly,while the peak load and ductility coefficient increased by about 35%.With the increase of plate thickness from 12 mm to 20 mm,the peak load of the specimen is increased by about 40%,the elastic stiffness is increased by about 90%,and the ductility coefficient is reduced by about 30%.Compared with the specimen with a loading angle of 0°,when the loading angle is 45°,the elastic stiffness of the specimen is increased by about 100%,and the peak load and ductility coefficient do not change significantly.When the loading angle is 90°,the elastic stiffness and peak load of the specimen do not change significantly,and the ductility coefficient is reduced by about 40%.