Strong-axis stability and seismic performance of perforated core plate buckling-restrained braces

Abstract

Perforated core plate buckling-restrained brace (PBRB) is a new type of energy dissipation device proposed recently. Several perforated zones are evenly distributed along the brace length of PBRB to dissipate seismic energy and separated by transition zones to improve their strong-axis stability. Previous studies showed that improper perforated core plate (PCP) configurations may lead to premature strong-axis buckling and rupture failure in the perorated zones. However, effect of the PCP configurations on the performance of PBRB still remains unclear. This study aims to investigate numerically and experimentally the influence of PCP configurations on the strong-axis stability and seismic performance of PBRB. Key parameters include the type of perforated zone, the length of transition zone, and the ratio between the length of a perforated zone and the width of a yielding segment. Numerical analysis shows that (1) the perforated zone with the semi-circle type is more beneficial in improving the stability and seismic performance of PBRB than the rectangle type; (2) The length of transition zone has significant impact on the stability performance of PBRB, and it is recommended to be no less than half the width of a yielding segment. Cyclic tests of three PBRB specimens with the semi-circle type were conducted, and the experimental and numerical results show that increase in the length of perforated zone is beneficial in improving the seismic performance of PBRB but may trigger strong-axis buckling in the perforated zone. A practical criterion to prevent the strong-axis buckling of PBRB is quantified by parametric analysis.