Modeling and behavior of composite MRFs with concrete filled steel tubular columns subject to earthquake loading

In conjunction with the U.S.-Japan Cooperative Research Program in Earthquake Engineering on Composite and Hybrid Structures, analytical studies on the seismic behavior of steel moment resisting (MRFs) with concrete filled steel tubular (CFT) columns were performed. The CFT columns consisted of normal strength concrete with a high strength steel tube. In these studies the seismic performance of this type of composite structure was investigated using a fiber element in order to account for nonlinear behavior due to material yielding, local buckling, and concrete cracking and crushing. Using the IBC 2000 provisions several frames were designed and analyzed. It was found that the frames are likely to perform adequately under both the design level and maximum considered earthquakes.