Scienceline Publications Journal of Civil Engineering and Urbanism 2252-0430 7 1 2016 January Finite Element Modeling of Connections to Concrete-Filled Steel Columns under Fire 18 24 http://www.ojceu.ir/main/attachments/article/56/J.%20Civil%20Eng.%20Urban.%207%20(1)%2018-24,%202017.pdf EN Hamid Reza Ashrafi Assistant Professor, Department of Civil Engineering, Razi University, Kermanshah, Iran Peyman Beiranvand PhD Candidate, Department of Civil Engineering, Razi University, Kermanshah, Iran Mohammad Reza Dadgar MSc, Department of Civil Engineering, Islamic Azad University, Abhar, Iran Soroush Dadgar MSc, Department of Civil Engineering , Razi University, Kermanshah, Iran Concrete-filled steel tubular columns have been extensively used in structures, owing to that they utilize the most favorable properties of both of constituent materials, ductility, large energy-absorption capacity, and good structural fire behavior. Concrete inside the steel tube enhances the stability of the steel tube, and the steel tube in turn provides effective lateral confinement to the concrete. Furthermore, the fire resistance of CFT columns is higher than that of hollow steel tubular columns, external protection being not needed in most cases. During a fire, the steel tube acts as a radiation shield to the concrete core and a steam layer in the steel-concrete boundary appears. This paper employs the general finite element software ABAQUS to numerically model the behavior of restrained structural subassemblies of steel beam to concrete filled tubular (CFT) columns and their joints in fire. The simulations were conducted using 3-D brick elements to enable detailed structural behavior to be obtained. For validation, this paper compares the simulation and test results for the three fire tests using reverse channel connection recently conducted at the University of Manchester. This comparison demonstrates that the 3-D finite element model is able to successfully simulate the fire tests. Afterwards, the validated finite element model was used to conduct a preliminary numerical study to investigate the feasibility of changing some of the connection details to enhance survivability of the structure in fire. Specifically, this investigation concentrated on developing connection methods to enable catenary action in the connected beam to be more fully developed. An example is to develop a hybrid flush/extended endplate and flexible endplate connection in which the tension part of the connection uses a flush/extended endplate for increased tensile resistance but the compression part of the connection uses a flexible endplate for improved ductility. It has been found that, without additional cost, using a hybrid extended/flexible endplate connection to replace a flush endplate connection has the potential to enable the connected beam to survive significantly increased temperature. Concrete-Filled Steel Columns Reverse Channel Finite Element Endplate