Numerical Simulation And Research On Fire Resistance Of Long - Span Cable Dome Structure

Under the high temperature of fire,the carrying capacity of the steel structure will be significantly attenuated.The danger of partial collapse may occur.Aiming at the lack of research on the mechanical properties of cable dome structures under high temperature in fire.In this paper,the mechanical characteristics of Geiger-type and composite-type cable dome structures under fire and high temperature conditions should be studied.The method “fire-resistant design of large span steel structures based on calculation” should be used to analyze the structural high temperature mechanical response.In order to achieve the purpose of providing different fire resistance requirements,different structural fire precautions are to be determined.Shortcomings in this method should be researched,and this method should be improved.The research contents and conclusions are as follows:1.The advantages and limitations of fire-resistant design method of component based on experiment was researched and analyzed.The analysis method for fire-resistant design of large span steel structures based on calculation was introduced,and the key problems to be solved in this paper was put forward.The basic principle of this analysis method is described.2.The temperature field of fire was calculated by fire-heating formula of tall space.The software ANSYS was used to study the mechanical characteristics of Geiger-type and composite-type cable dome structure under high temperature in fire and 47 models were calculated.The results showed that the vertical displacements of the Geiger-type and composite-type cable domes under high-temperature fire conditions are increased by 35% and 59% respectively.3.By ANSYS software analysis and comparison,the change of fire source location and fire source power had a great influence on the mechanical properties of Geiger-type cable dome and composite-type cable dome,while the combustion rate of fire source and the heat release power per unit area of fire source variations had little effect on the cable dome structure.We studied the necessity of considering the accidental load of fire,different locations of fire source and different power of fire source in the static analysis of cable dome structure,and give corresponding suggestions.4.Pyrosim software was used to carry out the accurate analysis of fire temperature field.Three typical fire scenarios were set up to explore the temperature fieldcharacteristics of Tianjin University of Technology gymnasium during fire development.The mechanical response characteristics of composite cable dome in the accurate temperature field of fire were studied.Calculated by ANSYS software analysis,composite-type cable dome structure which not coated with fire-retardant,the structure did not meet the requirements of fire-resistant load-bearing capacity.In accordance with the " Code for fire protection design of buildings " component fire safety requirements,the structure of 1.21 mm ultra-thin coating fire retardant coating,calculated to show the structure to achieve the requirements of fire-resistant capacity.As a result,the fire protection measures for the composite cable dome structure were optimized.It was suggested that the fire protection coating should be optimized to1 mm for the newly constructed gymnasium of Tianjin University of Technology.