Finite Element Analysis On Fire Resistance Of Large Space RC Structure

Along with the deepening of reform and opening up process, the social economy has experienced a rapid development stage, the development of domestic urbanization process is very fast. Such rapid construction has put forward new requirements to the firefighting cause. Because of the complex environment of the fire scene and the different construction standards in different periods, it is difficult for fire rescue personnel to make an accurate judgment of the risk of construction. At present, the research on the fire resistance of building is mainly focused on how to prolong the fire resistance limit of the building structure in the design stage, without the methods and tools for the firefighting personnel to judge the building safety. Thus, it caused many casualties and losses. The paper takes the reconstruction of large-scale supermarket as an example and applies the fire simulation software (FDS) and Finite element analysis software (ANSYS) to research the internal temperature changes, distribution of temperature field of building structure nodes, stress and deformation of building structures under the fire effect. Compared with the Simplified calculation method of internal force, the following work is made to seek for the method applicable to the structure danger analysis of firefighting personnel:1. Research the common causes for fire and then analyze taking certain supermarket as the research object, investigate the comprehensive fire load density and actual distribution of clothing in the supermarket. On this condition, FDS is used to analyze the environment temperature field distribution and actual fire temperature rise curve when the fire occurs to provide data foundation for the future finite element analysis.2. Study on fire resistance of building materials mainly is the Coefficient of thermal conductivity, specific heat and thermal expansion coefficient of reinforcement and concrete at different temperatures. The temperature field data are obtained from these data combining with FDS. And then, ANSYS is used to analyze the construction of reinforced concrete and beam column to obtain the temperature field of simulation.3. Based on the definition of equivalent stiffness, the algorithm of deformation and internal force of beam column element at high temperature is obtained. As for reinforced concrete frame structure, ANSYS is used to conduct Thermal structural coupling analysis and find the displacement of frame in vertical and horizontal direction, and temperature field distribution diagram and VonMises stress distribution diagram. Finally, compare the data obtained from simulation with the Simplified algorithm data of deformation and stress of column beam components in high temperature based on the definition of equivalent stiffness, describe the effectiveness of simplified algorithm in the error scope. Because the simplified algorithm is very simple, it may be used in the basic analysis of deformation and stress of frame structure in high temperature conditions.The work made in the paper plays reference effect on the future fire department in the aspects of preparing fire rescue plan, improving firefighting action and field battle command decision.