Testing on global stability performance of multi-celled CFST walls with three simply-supported edges

Abstract

Multi-celled concrete-filled steel tubular wall (MCFSTW) is a composite structural system. In engineering practice, MCFSTWs are always orthogonally arranged to form wall limbs with different section forms. For slender wall limbs, their global stability is widely concerned and deserves further investigation. To evaluate their global stability performance, the single wall limb isolated from the whole wall limb is commonly regarded as a wall member with lateral edges constrained by simple supports. In this study, experimental and numerical studies were conducted to predict the global stability resistance of MCFSTWs with three simply-supported edges. Firstly, three specimens were tested under axial compressive load. Based on the test results, the failure modes were discussed and summarized. Secondly, a refined FE model considering boundary constraints and deformations was developed. According to the orthotropic plate theory, the theoretical formula of the elastic buckling load for MCFSTW with three simply-supported edges was derived and validated. Then, the existing stability curves were verified by comparing them with numerical results. The results indicated that they are not adequately accurate for practical engineering applications. Finally, a stability curve was proposed by fitting the FE points and validated against the modified test points, indicating that the proposed curve is capable of predicting the global stability resistance of MCFSTWs with three simply-supported edges.