Cyclic Performance of Buckling Restrained Composite Braces Composed of Selected Materials

Concentric bracing is one of the most common lateral load resistant systems in building fram es. and areapplied to many structures due to their manufacturing simplicity and economics. an important defi ciency in thebracing members is their irregular hysteretic loops under cyclic loading. in order to overcome this problem. it isadvised to restrain braces against buckling under compression. since buckling restrained fram es dissipat e a largeamount of energy. one method to restrain braces against buckling is to cover them with concrete. a proper coveringcan prevent the core from buckling and provide similar capacities whether in tension or compression which wouldproduce regular hysteri c curves. in this study, the behavior ofbuckling restrained braces (brb) has been investigatedby considering different types of surrounding covers. the steel core is encased in concrete with different coverings. thecove ring types include steel tubes, pvc pipes. and frp rolled sheets. experimental and numerical analyses wereimplemented. according to the results, pvc pipes and frp sheets are suitab le alternati ves to steel pipes. furthermore.the behavior of several types ofsteel cores was assessed; since, applying steel with high ductility promot es the energydissipation of the brace. finally. the effect of the separating layer between the steel core and the concrete on theperformance (if bracing was evaluated.