Fire Resistance Analysis Of Truss Structure Under Large Space Building Fire

The aim of fire-resistance design of building struetures is to avoid severe damage orcollapse during fire attack. So then ensure personnel inside the building have enough time tosafety evacuation and fire rescue in the fire, and reduce the repairs of structure after the fire.At present, domestic and foreign related code all ensure the safety of overall structure in fireby guaranteeing the bearing capacity of separate components in the fire. Determine the fireresistance capacity of single member on account of the fire resistance performance of theoverall structure,which can more truly evaluate safety of the structure in the fire.As onecommon form of the roof structure in large space building, Plane truss structure which is fireresistant bearing capacity under the fire is important for ensuring fire endurance provided bylarge space building roof structure. This artical researches mechanical response of plane trussstructure In large space building under the fire, in order to get fire resistant mechanism of hetruss structure in the fire, so then provide a theoretical basis for doing fire resistance design oftruss structure. The specific research includes the following two aspects:（1）Based on nonlinear finite element theory, simplified structural analysis model byunifieding truss rod stress ratio, and then establish thermal coupling effect analytical mode oftruss structure.Using ANSYS in the step-by-step temperature procedure method to simulatethe whole mechanical response of truss structure in case of fire in the even temperature fieldand the uneven temperature field.（2）Investigate the effect of bearing boundary constraint conditions、temperature boundarycondition and loading ratio on critical temperature of truss structure.According to parameteranalysis,finally obtain the key parameters and failure mode of fire-resistant performance forplane truss structure.