Numerical Research On Integral Fire-resistance Of Double-layer Spherical Domes

Spherical domes is widely used within large space building. Fire safety of it must be studied. The normal indoor fire's temperature field is not suitable for the large space shell structure. Structure research of fire-resistant performance mainly depends on the fire-resistant analysis of the member at present. The material properties may be changed with elevated temperature and internal strain may be induced by thermal expansion in domes, so, through this method is very difficult to simulate entire process of the whole construction.Based on the problems in the fire-resistance research of spherical domes, firstly the Laoshan velodrome is takeed as the object of study and according to the structural feature two fire scenarios can be designed. The spherical domes is divided several region in term of smoke distribution pattern. The two scenarios may be simulated by computer programs"FDS"researched by United States in 2002 and actural temperature distribution nearby the shell can be gotten. Secondly establishment procedure is used to calculate the influence of important parameter to the temperature in unprotected steel members and members'temperature of each field. Lastly the entire process and the critical temperature can be analyzed under fire load by the generic finite-element stress-analysis program"ANSYS"according to the actual destruction characteristic of spherical domes. Influence to critical temperature by parameters must be considered respectively. Actural spherical domes'fire safety of every fire scenario is calculated under nouniform temperature field, and then the key member must be taked the protective measures of fire resistant is discovered. Security evaluation of Laoshan Cycling Museum can be tabled through analysis of advantageous and disadvantage factors.In actural fire scenarios,air temperature around the fire origin is higher and has the great gradient with other regions.The bigger is the F/V,the higher is the members'temperature.The bigger the load compared and nonuniform coefficient of temperature distribution,the higher is the critical temperature.In the first fire scenario,the structural integrity has not destroyed,while six members must be taked the protective measures of fire resistant as a result of local destruction. In the second scenario, members of the domes are not failure.