Cyclic Performance of a Piston Based Self-Centering Bracing System: Fid-Bau Portal

Cyclic Performance of a Piston Based Self-Centering Bracing System

Haque, A. B. M. Rafiqul / Alam, M. Shahria

The major difficulties faced with traditional structural bracing systems against seismic loading include compression buckling and permanent residual deformation under seismic loading. Once buckling occurs, the strength and stiffness of a brace gets significantly reduced and the stiffness degrades rapidly in subsequent load cycles. A significant number of researches have been conducted in resolving this issue and various ideas have been proposed and developed for the industry, e.g. buckling restrained brace, cast steel yielding fuse, SCED, MANSIDE, and RHDB braces, etc. Unfortunately, most of these solutions are expensive and complicated to construct. Authors here have proposed a novel approach in addressing this issue using a modification of a device commonly seen in mechanical systems, which is a cylinder-piston assembly. In this system, stiffness and re-centering are contributed by shape memory alloy ties. This study investigates the behavior of this innovative Piston Based Self-Centering (PBSC) bracing system in finite element environment. Utilizing this assembly, a brace member is able to carry large magnitude of tensile and compression loading without buckling. Furthermore, this brace is able to re-center after large nonlinear deformation. This paper presents the results of the analytical investigation carried out in ABAQUS software using finite element method. The load deformation hysteresis was determined and a flag shaped hysteresis was achieved, which indicates good re-centering capability of the proposed system.