High-mode buckling of buckling-restrained brace core plates

In this study, cyclic loading tests on three novel all-steel buckling-restrained braces (BRBs) are conducted to investigate the high-mode buckling phenomenon. The proposed BRB is composed of a steel core plate and two identical restraining members which restrain the core plate using shim spacers. The proposed BRBs can be visually inspected following a major earthquake. The two restraining members can be conveniently disassembled and the damaged core plate can be replaced if necessary. Tests confirm that the larger the axial compressive strain is applied, the shorter the high-mode buckling wavelength would be developed. The weak-axis buckling wavelength is about 11 to 12 times the core plate thickness when a core compressive strain of 3.5% is reached. Tests indicate that the proposed BRBs can effectively sustain large cyclic strain reversals. The high-mode bucking wavelength can be satisfactorily predicated using the proposed method.