Buckling-restrained braces (BRBs) are widely used to improve the seismic performance of high-rise and long-span structures. This study proposes a triple-tube GFRP–steel buckling-restrained brace (TTGS-BRB) as a lightweight and corrosion-resistant energy-dissipating member for such structures. To investigate its hysteretic behavior, pseudo-static tests were conducted on two scaled TTGS-BRB specimens with different wrapping orientations and end details, and a finite element model was established and validated against the test results for further parametric analyses. The test results showed that the specimen with the ±30° wrapping configuration and end stiffeners exhibited better hysteretic performance than the 90° specimen without end stiffeners, with the yield force increasing from 147.98 kN to 161.68 kN, the cumulative plastic deformation (CPD) increasing from 7.49 to 209.56, and the cumulative plastic energy (CPE) increasing from 5.25 to 199.12. Based on the validated finite element model, the effects of fiber wrapping orientation, end stiffeners, interfacial gap, Pcr/Py ratio, and steel tube diameter-to-thickness ratio on the hysteretic performance of full-scale TTGS-BRBs were systematically investigated. The numerical results indicate that wrapping orientations within the range of ±0° to ±45°, end stiffening at both ends, an interfacial gap of 1.5 mm between GFRP and steel, an appropriate Pcr/Py ratio, and a steel tube diameter-to-thickness ratio of less than 24 are beneficial for improving the hysteretic performance of TTGS-BRBs. These findings provide useful references for the design and application of TTGS-BRBs in practical engineering.
Ma et al. (Mon,) studied this question.