Buckling behavior of double skin composite walls under axial compressive load

Abstract

In this paper, the steel faceplate buckling of double skin composite walls stiffened with studs or steel-bar trusses is studied and analyzed by the axial compressive test, including ten specimens. According to the investigation, the buckling mode of steel faceplate, whose restraint situation is four points arranged in different shapes, is observed, and the calculated equation of buckling stress is proposed. Based on the test, the buckling strain monitored by strain gauges and maximum strength increases with the decline in welding spot spacing-to-thickness ratio and spacing aspect ratio. According to the finite element model (FEM) established by ABAQUS, the failure mode of the walls is simulated well. The buckling stress and load–displacement curve obtained by FEM corresponds well with these of the test. The parametric analysis is conducted to study the influence of initial geometric imperfection by considering the welding spot spacing-to-thickness ratio and spacing aspect ratio on faceplate buckling stress. When the initial geometric imperfection is larger than 1/1000 of the vertical welding spot spacing, the faceplate buckling stress drops more slowly with the increase of initial geometric imperfection. The relationship between the buckling stress and welding spot spacing-to-thickness ratio obeys the Euler curve. The buckling stress of the steel faceplate decreases linearly with the increase in the spacing aspect ratio. The results by using the buckling equations with the consideration of the initial geometric imperfection and spacing aspect ratio are approximately in accordance with the simulated results.