Seismic Tests and Finite Element Analyses of Buckling Restrained Braces with a Replaceable Core Plate
|關鍵字:||挫屈束制支撐;可更換核心板;有限元素分析;BRB;Replaceable Core Plate;Finite Element Analyses|
This research presents the results from component tests and finite element analyses on a proposed type of a steel buckling-restrained brace (BRB) with a replaceable core plate. The proposed BRB is composed of two components: (1) a steel core element that carries the entire axial forces during both tension and compression and (2) two restraining elements that are bolted to prevent the core from buckling in compression. Since the two restraining elements are easily assembled and separated, the steel core can be replaced if it is damaged after cyclic loads. Four full-scale BRB subassemblages were tested based on AISC (2005) seismic provisions to investigate inelastic cyclic deformation capabilities and verify theoretical predictions on the structural stability of the braces. Test results indicated that three proposed BRBs with sufficient out-of-plane restraining stably sustain severe inelastic axial strain reversals up to 2.1%, and develop a cumulative plastic ductility capacity much higher than that specified by AISC (2005). However, one BRB, designed with inadequate out-of-plane restraining, experienced global flexural buckling after a large number of inelastic reversals. Non-linear finite element analysis conducted for each BRB showed that the ultimate compressive strength and post-buckling behavior could be predicted if the initial geometric imperfections were considered in the model. A parametric study was also conducted for 18 BRBs using the non-linear finite element computer program ABAQUS to further verify the effectiveness of the restraining element and number of bolts to prevent the core from global and local buckling. A design procedure for the proposed BRB was provided based on the test and analytical results.
|Appears in Collections:||Thesis|
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