The Analysis Of Mechanical Properties Of Ribbed Spherical Reticulated Mega-structure Under Fire

The reticulated mega-structure has favorable mechanical property, elegant outline, considerable stiffness and light weight; thereby it is suited for the functional large-spanstructure and has extensive application prospect.The steel structure could be easily damaged or even collapse because of poor refractory performance of steel if fire happens in the steel structure building.For statically indeterminate reticulated mega-structure,the high temperature of fire field can change the steel material property and lead to temperature stress in the structure, so it is necessary to further research mechanical properties of ribbed spherical reticulated mega-structure under fire to ensure structural safety.The ribbed spherical reticulated mega-structure is the main researching target in this paper and the ascending air-temperature model forhigh-large spatial structure is adopted to simulate the temperature in fire filed. The effect of height, location and number of fire resource onthe variation of joint displacement, axial force of element and support reaction are analyzed using finite element software ANSYS, the varying law of which is summarized. The influence of fire parameters(height, location and number of fire resource) on structural static performance is also studied.Structural stable bearing capacity under various fire factors(height, location and number of fire resource) are solved by Newton-Raphson method considering the geometrical and material nonlinearity. The influence of structural parameters such as vector-span ratio and truss height of beam on structural stable bearing capacity under fire action is studied.