Safety Evaluation Method For Key Components Of Steel Frame Under High Temperature Fire

Steel is recyclable material. From the view of environment protection, Steel structures has the advantages that the concrete structures have no. High strength, good seismic performance, light weight and convenient construction are main features of the steel structures. In recent years, China’s steel production has been increasing, so far, China is the world’s largest iron and steel producer. Because of overproduction,the lower price of the steel has promote the develop of the steel structures, but compare with the concrete structures, the fire protection and fire resistance of the steel structure are the big problems.There are many research and engineering practice about the evaluation of steel structure at home and abroad, but there is not a systematic theory support practice.Generally, judgments by the relevant professional standard rules and characteristics data of the material. Safety evaluation conclusion depends on the professional level and experience of the employee. Safety evaluation conclusion depends on the professional level and experience of the employee,its development is extremely lagged behind the current structure design theory and exploration techniques. In domestic, there are few steel structure fire(high temperature) safety evaluation method.This thesis contains following context:(1) The computational model of axially compressed steel column, Fixed steel beam with two ends and the Bending steel column has set up. Using theoretical formula to calculate the bearing capacity of the component under normal temperature and high temperature, and compared with the numerical simulation results, it can be concluded that the bearing capacity of the component is greatly reduced at high temperature.(2) Using finite element method software ANSYS Thermal mechanical coupling analysis, a two story two span steel frame has been analyzed and the stress distribution of each member has obtained. The material parameters of the computational model adopt the parameters that the steel under high temperature(fire) and using ISO834 standard heating curve. According to the average value of the maximum stress and the minimum stress of the component and the ratio of the yield strength of the material under the fire condition, the key component of the temperature condition is defined.(3) Collect related literature,learning and understanding of international and domestic steel structure fire resistance,determine the key components, fire steel member safety evaluation method. Based on the former research, summarized the concrete content of the fire scene investigation,as well as the statistics of the number of combustible materials, pointed out the fire load density, and the characteristic fire load density of various types of building is given. The method of estimating the fire duration and the temperature of the fire is summarized. Combine with the calculation results of the bearing capacity of the member under the high temperature(fire), a safety assessment procedure of the key components of steel frame under fire is formed and applied in engineering cases.Based on the strength and deformation of the component to determine whether the component need to reinforcement, to avoid blind reinforcement, and keep safe.The key component of steel frame under high temperature and fire safety evaluation method research, looking for the steel structure building fire safety appraisal and reinforcement to provide reference for reference.