Investigation On The Fire Resistance Performance Of Composite Cellular Beam And Cellular Steel Frame

Cellular composite beams are made up of cellular beam and concrete floor through the stud,which can work together,have a good performance in structure,its biggest advantage is that combine the characteristics of the steel structure and the reinforced concrete together,Make the force more reasonable,more widely applied and has significant economic benefit and theoretical research meaning,this structure can suit our country national condition and the sustainable development of green construction.Steel is non-combustion material,but its yield strength and Young’s modulus degrade quickly at high temperature,which makes the steel structure have a low fire resistance,the fire in the building may cause global collapse to the steel structure or severe damage to structural components.It is necessary to study the composite cellular beam behavior under fire to provide cellular analysis theories and calculation methods of steel structure.In this paper,we carry out numerical simulation research on composite cellular beam and cellular steel frame structure in the perspective of fire resistance under the condition of temperature rise,which is conducive to the steel structure in the form of diversification,Meet the needs of the rapid development of economy in China,supplement and improve the cellular steel structure of the research content and provide related technical provisions,for the formulation of relevant national and local standards and industry standards to provide the reference.In this paper,we carry out the fire resistance research of cellular composite beams,mainly study the composite cellular beam’s critical temperature,failure mode,influencing factors,mechanical characteristics,temperature distribution under the fire conditions,compare the single composite cellular beam with the beam in the steel beam structure stress distribution,combining theoretical analysis with the finite element analysis,divided into the following three parts:cellular composite beams temperature distribution under the fire condition;single cellular composite beam critical temperature under standard fire and damage mechanism discussing the influence factors of fire resistance,including load size,the thickness of the web,groove,opening rate;in a single common cellular-beam steel framework,under the constraint of a column of honeycomb composite beams under fire,the failure mechanism and failure process and compared with the stress of the separate components,discuss the load size,groove,the beam end first open distributed the distance of the heart from the column flange three factors on the bearing capacity of the critical temperature and the influence.Research shows that:the stiffening rib can effectively guarantee the cellular composite beams under fire conditions of web local stability,prevent bottom flange lateral displacement caused by web buckling,which can improve the fire resistance performance of composite cellular beams under fire.The load,the opening rate and hole spacing have great influence on the fire resistance,web plate thickness is important significance to guarantee the stability of web local,but has little influence on the bending stiffness of cellular composite beams under fire and critical temperature.The pass(for the hexagonal hole and round hole)have less effect on the critical temperature,in a single common cellular steel framework,pass and node distance from the first opening of the influence on bearing capacity is larger,in the condition of vertical load,composite cellular beam bottom flange instability phenomenon happens.The results above,can provide a foundation for the further study of the fire resistance of cellular beam.