MECHANICS AND PERFORMANCE STUDY OF SELF-CENTERING VARIABLE DAMPING ENERGY DISSIPATION BRACE

A new self-centering variable damping energy dissipation brace is proposed to solve the high sliding force problem of existing self-centering braces. Combination disc springs are used to provide a self-centering behavior, and magnetorheological fluid variable damping energy dissipation is realized by construction design. Variable damping characteristics of the brace are analyzed, a restoring force model is developed to describe its hysteretic behavior, and the design boundary conditions based on performance requirements of the brace are proposed. The whole brace and magnetic field of damping energy dissipation device are simulated. Research results indicate that:the brace exhibits full similar flag-shaped hysteretic curves with a low sliding force, no residual deformation, and the symmetry of tension and compression. And performance requirements under different vibration levels are considered to effectively control the structural vibration responses. The effects of design parameters on hysteretic behaviors of the brace are analyzed. To improve the behaviors of self-centering and energy dissipation, the pre-pressed force of combination disc springs should be larger than the initial damping force, meanwhile, the stiffness of combination disc springs and the maximum damping force should be increased, and the variable damping region should be decreased. Compared with the existing self-centering braces, the sliding force of the proposed brace is lower, the sliding stiffness ratio is higher, and the equivalent viscous damping ratio and the maximum bearing capacity with the same design of self-centering device are also increased.