Local and post-local buckling of steel-concrete composite panels under combined states of stresses

Steel plates in double skin composite (DSC) panels used as two-way slabs or shearwalls may buckle locally in one lateral direction between stud shear connectors when subjected to combined states of stresses. The local and post-local buckling strength of steel plates in biaxial compression and shear is studied in this paper by using the finite element analysis method. Critical buckling interaction relationships are obtained for steel plates with various boundary conditions. A geometric and material nonlinear analysis incorporating initial imperfections of plates, material stress–strain law and nonlinear shear-slip behaviour of stud shear connectors is undertaken to quantify the post-local buckling interaction relationships of steel plates. Design models are proposed for determining critical buckling and ultimate strength of plates in DSC panels.