Experimental study on bending strength of high-strength cold-formed thin-walled steel channel section members

Bending behaviors of 550 MPa high-strength cold-formed thin-walled steel channel section flexural members with stiffener types and edge stiffener types were studied through the static experiments of 36 specimens, where the three types of stiffening schemes were without stiffeners, with intermediate V type stiffeners in the flanges and with intermediate V type stiffeners in the flanges and the web respectively, and the three types of edge stiffeners were upright, inclined and complex edge stiffeners respectively. It is shown that stiffener types and edge stiffener types are key factors that influence the member's bending strength and buckling modes. Compared with the case without stiffeners, the bending strength of members with intermediate V types is increased about 30% to 70% because the element width-to-thickness ratio is reduced effectively. In the same stiffener, bending strength of short (upright and inclined) edge stiffeners specimens is the maximum, bending strength of complex edge stiffeners specimens takes the second place, and bending strength of long (upright and inclined) edge stiffeners specimens is the minimum. Local buckling, distortional buckling and interaction of local and distortional buckling are observed in the test. The tests were simulated by finite element and the simulation results agree well with the test results. ©, 2015, Science Press. All right reserved.