High-mode buckling responses of buckling-restrained brace core plates

Cyclic loading tests and finite element analyses on six novel all-steel buckling-restrained braces (BRBs) are conducted using different loading patterns to investigate the core plate high-mode buckling phenomenon. The proposed BRB is composed of a core member and a pair of identical restraining members, which restrains the core member by using bolted shim spacers. The design of the proposed BRB allows the core plate to be visually inspected immediately following a major earthquake. If necessary, the pair of restraining members can be conveniently disassembled, and the damaged core plate can be replaced. Test results indicate that the proposed BRBs can sustain large cyclic strain reversals and cumulative plastic deformations in excess of 400 times the yield strain. Experimental and analytical results confirm that the high-mode buckling wavelength is related to the core plate thickness and the applied loading patterns. The larger the axial compressive strain is applied, the shorter the high-mode buckling wavelength would be developed. The buckling wavelength is about 12 times the core plate thickness when the high-mode buckling shape is fully developed. However, it reduces to about 10 times the core plate thickness when a compressive core strain reaches greater than 0.03. The high-mode bucking wavelength can be satisfactorily predicted using the proposed method or from the finite element analysis. Copyright (c) 2013 John Wiley & Sons, Ltd.