Failure Mechanism And Bearing Capacity Calculation Of Composite Slab Beams With Beam End Restraints Under Fir

Composite slab composite beam is a new type of composite structure developed on the basis of traditional composite beam.It not only has the advantages of high bearing capacity,high stiffness and giving full play to the material properties of traditional composite beam,but also can save the number of supporting process and formwork,reduce the amount of wet concrete work on site,facilitate three-dimensional construction,and has good economic benefits.According to the situation of green sustainable development under double carbon goal.At present,most of the existing studies have taken simply supported composite plate composite beams as the research object.However,the specimens in practical engineering are constrained by the surrounding components,and their mechanical properties under high temperature are much more complicated.Therefore,in order to better conform to the practical engineering,it is necessary to carry out further experimental research and theoretical analysis on the composite beam with beam end constraint composite plate.Based on the summary of the research results of domestic and foreign scholars and national standards,the appropriate thermal physical parameters and mechanical properties of materials under high temperature were selected.A finite element software,ABAQUS,was utilized to construct a model after a composite beam with beam end constraint was tested,and thermal-mechanical coupling analysis was then conducted.Verifying the accuracy of the finite element model,a comparison was made between the test results of temperature field and displacement.The effects of constraint type,flange form,flange width,flange thickness,and web height were also taken into account.The fire resistance of composite plate composite beams is investigated through the examination of web and composite plate thickness.Results demonstrate that the fire resistance of composite plate composite beams is largely determined by constraint type,wing plate form,web height,web thickness,and composite plate thickness;when other conditions are taken into account.When the beam end restrictions are more stringent,composite composite beams demonstrate a heightened fire resistance.The fire resistance of composite beams with monolithic beam end constraints is more powerful than that of beams with separated beam end constrain.An analysis of the fire resistance limit and bearing capacity of composite beams with beam-end constraints,based on a fire resistance analysis model,was conducted through both high temperature transient and steady-state analysis.Additionally,the effects of constraint type,flange form,flange width,flange thickness,web height,web thickness,load ratio,and composite plate thickness on the fire resistance and flexural capacity of composite plate beams with constraint end were explored.The results demonstrate that web height,flange height,and flange thickness have minimal influence on the bearing capacity coefficient of composite beams with constrained composite plates at the beam end,but the web thickness does have a considerable impact.The bearing capacity coefficient of a composite beam with a constrained composite plate at the end is significantly impacted by its flange form and composite plate thickness,as well as the load ratio and thickness of the composite plate.The fire resistance of composite beams with beam-end restrictions is significantly impacted by the web’s thickness and height.The fire resistance of composite beams,with beam-end restrictions,is not significantly impacted by the width or thickness of the flanges.A presentation of the practical technique for computing flexural bearing capacity and fire resistance of a composite beam with a beam end restriction is provided.The finite element results,which can be used as a reference for fire resistance design in related engineering,are in close agreement with the results.