腹板开边缘加劲孔的折叠翼缘冷弯薄壁C形钢受弯构件稳定性能研究OA

In order to investigate the effect of edge-stiffened holes in webs on the stability performance of folded-flange cold-formed thin-walled C-shaped steel flexural members,stability tests and finite element simulations were conducted on three types of specimens-specimens without web holes(Fl),specimens with ordinary web holes(F2),and specimens with edge-stiffened web holes(F3)under pure bending and combined bending and shear conditions.The results show that edge stiffening suppresses local buckling in hole regions under pure bending and weakens its coupling with distortional buckling.Specifically,F1 and F3 specimens fail in distortional buckling,whereas F2 specimens exhibit interactive local-distortional buckling.Under combined bending and shear,edge stiffening improves web shear transfer performance and reduces deformation around holes under bending-shear coupling.Specifically,F1 and F3 specimens both exhibit interactive buckling of local and distortional modes,while F2 specimens underwent local buckling.Compared with F1 specimens under identical conditions,the flexural capacities of F2 and F3 specimens decrease by 7.55％and 3.49％(pure bending),and by 35.46％and 8.18％(bending-shear coupling),demonstrating that edge stiffening of holes can significantly mitigate the reduction in load-carrying capacity of perforated specimens under bending-shear coupling.In addition,referring to the methods in relevant literature,a reduced plate thickness formula was established for F3 specimens to determine the critical elastic distortional buckling stress,and a direct strength method(DSM)study was carried out on the flexural capacities of the three types of cold-formed thin-walled C-shaped steel under pure bending.The results show that the flexural capacity predictions obtained using the proposed formula agree well with the test results and exhibit low scatter.