Numerical and experimental studies of corrugated-web-connected buckling-restrained braces

Abstract

This paper proposes a new type of buckling-restrained brace (BRB), the so-called corrugated-web connected buckling-restrained brace (CWC-BRB), which is a core-separated BRB. The external restraining system of the CWC-BRB is composed of two all-steel external tubes connected by either single or double sinusoidal corrugated webs. Each of the two cores of the CWC-BRB has a single steel plate section and an extended projection at each end of the CWC-BRB, and the two core projections at each end are connected by a core stiffener. The external restraining systems, corrugated webs, two cores and core stiffeners form a firm and robust I-section CWC-BRB, and the flexural stiffness and load-carrying capacity of the proposed steel CWC-BRB are much larger than those of ordinary single-cored steel BRBs. The elastic buckling load of the CWC-BRB is derived by considering the shear deformation of the corrugated webs in the external restraining system. The ultimate load-carrying capacity under monotonic axial compression of CWC-BRBs and their hysteretic and low-cycle fatigue performance under repeated compressive-tensile cyclic loads are investigated using a shell element FE model. In addition, the effect of the restraining ratio or normalized slenderness ratio on the load resistance and failure mode of a CWC-BRB is explored. To further investigate the hysteretic performance and corresponding failure modes of CWC-BRBs and to validate the FE model, experimental studies are reported on four CWC-BRB specimens: two having a single sinusoidal corrugated web and other two having double sinusoidal corrugated webs. It is shown that the FE model provides excellent correlations with experimental results.