Reaction Analysis For Steel Structure Of Building In Fire

In recent years, fire mishaps often occur in large malls. Due to its large quantity combustible materials,staff-intensive,it is always engender great loss of property and personnel. Steel is not fireproof, which mechanical property decrease severely in high temperature. In case of a fire,the steel structure is damaged easily,therefore the steel structural safety of larges marketplaces in fire become a widely concerned problem.The ISO834 standard warming up curve has often applied as ambient temperature on steel structure in the traditional design of resistance to fire, however, the practice proves that different fire sites have different heating-up trend,sometimes there are huge difference for the large scale building especially. At present, the steel structure design of resistance to fire still utilizes the component design method of resistance to fire based on experiment, which is simple, direct visual and convenient, but the destabilization one of the components in fire do not result in overall structure destabilizing consequentially,which may be have the load-carrying ability resistance to fire.Fire modeling and steel structure safety of mall are studied by ANSYS software in this paper. The main completed research contents have as follows:1. The real ambient temperature was calculated by FLUENT of ANSYS software.2. The temperature field of the steel flame of mall was simulated in the real ambient temperature and ISO834 standard warming up curve, then compared them each other.3. Establish the steel frame under the external force load and the temperature load together function stress model, synthetic considered the material non-linearity, analyze the couple of thermal-structure on overall steel frame structure by ANSYS software.The results show that the structure analysis of resistance to fire in the real ambient temperature sometimes has large difference from in ISO834 standard warming up curve, and it can truly reflect structure response of resistance; the biggest displacement occurs in the intersection of ring-steel beam and straight beam; a higher displacement gradient exists within the straight beam; the displacement gradient is nearly uniform; Steel frame's performance of resistance to fire is much better than component.The study in this article has the certain the reference value to the fire resistance design of structure construction of the large scale building. The study in this article has the certain the reference value to the fire resistance design of structure construction of the large scale building under the real fire function.