Study On Fire Resistance Of Connections In Steel Frame Structure

In recent years, the steel structure is playing an increasingly important role in the field ofconstruction works along with the rapid development of Chinese economy. The steelconstruction possess many advantages，for example,beautiful, diversified building size, low cost,short construction period,high degree of mechanization and simple installation, which werewidely used in modern buildings. Steel beam-column joints play a crucial role as an importantpart of the steel construction to maintain steel overall performance. End-plate connections areone of the common ways of steel beam-column joints connected at high temperatures, due toexternal forces, the end-plate connected to a node will have a lot of deformation likely to causestructural damage, so it is essential to research the high temperature of the bottom plateconnection beam-column joints.This paper was carried on some simple introduction on the fire resistance of steel structuresand components protection method, a summary of the components of end-plate connections athome and abroad. The basic functions of the thermal performance of steel and ANSYS finiteelement simulation were introduced to provide a theoretical basis.Because component in thebeam-column joints were considered as the focus of the study, most of the components werewrapped with ceramic fiber in the numerical simulation, while the beam-column joints andnearby areas were exposed to the outside by the finite element calculation of components infailure modes under different operating conditions, so as to arrive at room temperature and hightemperature of the beam web and end plate junction is the main component damage region, andthe use of finite element simulation of the experimental conditions. On this basis, again usingANSYS finite element model of the analog components surrounded by the fire conditions, thetemperature field node, the node beam end displacement, stress distribution, failure mechanismsare analyzed, and draw some for the future engineering practice with reference to significantconclusions:(1)By means of finite element simulation,12load angle curves of different angles anddifferent temperature were drew, at the same time, the curves and the experimentally measuredexperimental curves are compared and analyzed, which obtained very good fitting effect in orderto verify the correctness of the results of experiment.(2)Experimental and finite element simulation can be seen that the destroyed area of thebeam-column joints of the recessed end-plate act as beam web and end-plate connection area,which prone to fracture in this area.(3)With increasing temperature, the steel mechanical properties and carrying capacity of thestructure are gradually reduced. However, in the same temperature under different angles,there is no direct relationship about the bearing capacity of the structure and the rotation capacityand load angle.(4)By finite element simulation can be seen in the external force remains constant withincreasing temperature, the corner of the node with increasing temperature is increasing. Thisshows that the strength of the material being reduced gradually with the increasing temperature,From the node temperature rotation relation can be found that before450℃, the angle changeswith increasing temperature is not particularly obvious, however, when the temperaturecontinues to rise, the rotation capacity of the noderapidly increased, and when the temperaturereaches about700℃,corner drastic changes. This structure has been the trend of destruction. It can be seen from the680s of the Von-Mises stress in the case of being encircled by fire, the end-plate is destroyed before the other components. Therefore, for within the contraction end-plateconnection components, for the end plates of the research is very necessary.