Cyclic Behavior of Corrugated Double-Skin Composite Walls with Different Aspect Ratios

Abstract

Experiments and finite element (FE) simulations were conducted on corrugated double-skin composite (Co-DSC) walls consisting of concrete-filled steel tubes (CFTs) and corrugated steel faceplates connected by tie bolts with concrete infill. Three specimens with different aspect ratios and one additional specimen with reinforcing sheaths at the bottom of CFTs were tested under combined axial and cyclic lateral loads. The specimens experienced a similar damage progress involving steel tubes and faceplates buckling and subsequent steel tube fracture. Both the steel tubes and faceplates experienced significant shear; however, the bending moment was predominately resisted by the CFTs. While the slender walls yielded due to flexure, the squat wall yielded due to both flexure resisted by the steel tubes and shear by the corrugated faceplates. All specimens experienced significant shear deformation and achieved a drift ratio capacity exceeding 1.9% and a ductility ratio greater than 3.2. FE models were developed and validated using the test data. The effects of major parameters, including aspect ratio, axial load ratio, and CFT bottom reinforcing method, were examined using the validated models. The numerical simulations indicated slender Co-DSC walls were more sensitive to the axial load ratio. Moreover, using sufficiently thick reinforcing sheaths at the CFT bottom could effectively delay strength degradation. Equations for calculating the lateral strength of Co-DSC were provided.