SEISMIC SIMULATION ON STEEL BEAM TO CONCRETE FILLED DOUBLE-SKINNED STEEL TUBULAR COLUMN COMPOSITE FRAME WITH BOLTED END-PLATE CONNECTIONS

This paper introduces an innovation composite concrete filled double-skinned steel tubular (CFDST) column frame system with bolted end-plate connections, which can improve the workability of composite structures by reducing in-situ welding labor workloads as well as seismic performance of traditional concrete filled steel tube structures. Simulation studies of seismic behavior of bolt-endplate connected composite structural systems consisting of CFDST columns and steel beams frame with reinforced concrete slabs are presented. According to current seismic provisions and recommendations from previous research, a typical ten-story prototype frame building is designed and performance objects of the bolted end-plate CFDST connections corresponding to three different earthquake hazard levels are proposed. Based on fiber section model, analytical models were developed to predict the elastic-to-plastic behavior of the prototype frame under both monological loading and a series of ground motion records. Analysis results indicated that the structural behavior under the simulated seismic loadings was consistent with the expected performance objects for different earthquake hazard levels corresponding to current seismic design codes, implying that effective seismic performance of composite CFDST frame with bolted connections can be achieved. The primary analytical simulation shows the suggested bolted endplate CFDST system has the potential to offer appropriate strength and adequate stiffness for buildings located in areas of high earthquake intensity, and provides basic information for further experimental researches to validate the seismic performances of the bolted end-plate CFDST structures.