Study On Fire Response And Collapse Mechanism Of Air-supported Structure

Inflatable membrane structure is a kind of structures using high performance membrane as the wall.Air supported structures refers to the structure whose membrane surface does not form a closed surface.The closed space of air-supported structures was parceled by membranes,foundation and indoor ground.The structures can with a stable form by pressure difference between inside and outside the membrane surface.Air-supported structures have been widely used in warehouses,stadiums,and public buildings.The membrane is both the stress-bearing component and the enclosure component at the same time.Damage to the structure may lead to large deformation and collapse of the entire building.Only the membrane selection of air-supported membrane structure is required in current codes,but the calculation method of the overall fire resistance of the structure is not given.Therefore,it is necessary to study the fire safety of air-supported membrane structure.The main research contents of this paper include:Study on the mechanical properties of PVC membranes at high temperatures.The methods of elastic modulus and strength reduction coefficients of PVC membrane at high temperature were proposed through experiment and numerical models.A method for estimate the strength reduction coefficient of weld joints of PVC membrane at high temperature was proposed.The meso-finite element model of PVC membrane was built and verified through cross validation.The type I and type III tear strength of PVC membrane at high temperature were researched by experiments and numerical calculations.Study on the collapse mechanism of air-supported membrane structure.Through collapse experiment and numerical models,the air leakage law of the air-supported structure under different internal pressure was proposed,and the method to estimate the equivalent natural leakage area of the air-supported structure under different pressure difference was proposed.A quasi-static fluid-structure interaction model was proposed for implicit dynamic analysis.The fluid-structure coupling response of air-supported structures in collapse cases can be quickly solved by using this model.Study on the whole process of fire temperature rising,membrane failure and collapse of air-supported structure.The whole-process analysis work flow of temperature rising,membrane failure and collapse of air-supported structure under fire condition was proposed.The whole-process fracture in fire cases of different air-supported structures was proposed.The influence of different factors on fire collapse behavior of air-borne membrane structures is studied.