Identifications of symmetric ductile braced structure by pseudo-single-degree-of-freedom procedure

Abstract

For energy-dissipation devices, identification of the physical behavior is a more difficult task than their design. This study develops an identification technique that is useful for the acquirement of the dynamic characteristics of buildings with symmetric ductile braces (SDBs) which exhibit bilinear behavior. The considered system is a linear multi-story building with SDBs regarded as a bilinear hysteretic model. The complex multi-degree-of-freedom problem was solved in the pseudo-single-degree-of-freedom domain, and the dynamic parameters of primary building as well as the SDBs are sequentially identified from top to bottom stories based on the input and output responses of floors. To simplify the nonlinear problem, a backbone curve, where the multi-values restoring force is transformed into a single-valued function, is applied to characterize the hysteretic model. A numerical study demonstrates that the proposed identification technique was able to extract the physical parameters of the primary building and the SDBs individually from the floor responses. It may be applied to the health monitoring of buildings protected by nonlinear energy-dissipation devices.