The Numerical Study About The Fire-Resistant Of The Whole Steel Structure In Large Space

Reticulated shell structure has many advantages, such as light weight, large spacestiffness, strong integrity, good seismic behavior and beautiful overall modeling. It has beenwidely used in the big span gymnasium, terminal, galleries and large public places in recentyears. Poor refractory performance is steel fatal weakness. If a fire happens in the steelstructure building, the structure is easy to be damaged or even collapse.At present, the member fire resisting design method is usually used on the study offire-resistant of the structure, but the overall effect is ignored generally. For staticallyindeterminate reticulated shell structure, the temperature in fire can change the steel materialproperty, lead to produce temperature stress in the structure. So it is necessary to furtherresearch on fire-resistant of the structure, mastering the fire resisting behavior of reticulatedshell structure in the fire is good to ensure safety.According to the deficiencies of reticulated shell structure research，a typical doublespherical reticulated shell structure was chosen to study fire resisting performance. First of all,the worst fire scenarios are designed based on the building structure features and fire dangercharacteristics. By using the FDS software to simulate the temperature field of the large space,it’s found that the temperature is low and has a big difference with ISO834. Considering thecharacteristics of structure form and the temperature field distribution, the large spacetemperature field is divided into some regions, and temperature load is provide for structureanalysis under high temperature. Secondly, based on the steel high temperature performanceparameters and steel member warming model, the influence of the large space fire radiationand shape factor F/V of component on the steel member temperature are analyzed. Then usingthe finite element software ANSYS for the analysis of fire resisting performance underdifferent load effect combination, as well as the variation and distribution of the structuredisplacement and internal force, it’s showed that under high temperature, the notedisplacement of reticulated shell structure and member stress increase along with the rising oftemperature. Finally, the safety of the structure on fire resisting is evaluated and it’sdetermined whether to take other fire protection measures.