Study On Progreesive Collapse Behavior Of Reinforce Concrete Beam Based On GFRP

The continuous collapse is the accidental load of the architectural structure due to natural factors or terrorist attacks.The continuous reaction caused by the destruction of the key parts of the structure causes damage to the structure of the surrounding structures.Eventually the disproportionate collapse of the structure.The occurrence of a continuous collapse will cause serious loss of life and property.Therefore,the way to strengthen the beam and column structure is increasingly attracting the attention of the engineering community.Because the GFRP material is economical and economical,it has a broad prospect in the field of structural reinforcement.In this paper,GFRP cloth is used to reinforce the steel bar in the upper part of the beam.In order to study the effect of whether adopt GFRP reinforcement,GFRP reinforcement methods and the number of GFRP reinforcement layers on the structural resistance to continuous collapse.By the analysis of five beam and column structure models by finite element analysis software.The theoretical analysis of the model is based on the classical elastoplastic theory.The main contents of the study are as follows:1,The basis of each model is a layer of 4 span RC beams and columns.The pseudo-static numerical simulation of anti continuous collapse is carried out respectively in the unreinforced model and the model of reinforce the upper and lower surface of the beam with one layer GFRP cloth.By comparing and analyzing the influence factors of displacement load curve,the displacement axial force curve,the stress of the key section of the beam,and the peak load capacity of the beam mechanism and catenary mechanism stage.On the basis of the truncation of the steel bar on the upper part of the beam,the performance of the beam-column structure strengthened by GFRP cloth to resist progressive collapse will be studied.2,The continuous collapse process of RC beam and column structure is divided into beam mechanism ?compound mechanism ?catenary mechanism according to different stress conditions.Based on the theory of structural mechanics and elastoplastic theory,the theoretical analysis of the calculation formula of the peak bearing capacity of the beam mechanism and the catenary mechanism is obtained.It is found that the simulation values of the unreinforced model and the model of reinforce the upper and lower surface of the beam with one layer GFRP cloth are in good agreement with the calculated values.3,After the analysis of the strengthened model and the unstrengthened model.It is found that the reinforcement of the steel bar on the upper part of the beam by GFRP can effectively improve the bearing capacity of the catenary mechanism in the RC beam and column structure.On this basis,the enhancement effect of different GFRP cloth consolidate methods and the number of consolidate layers of the structure in defending continuous collapse will be researched.The oblique anchorage hoop is better than the lateral anchorage hoop on the basis of the upper and lower surface of the beam strengthened by one GFRP sheet.The anti collapse bearing capacity of the structure increases with the increase of the number of reinforcement layers,but thenumber of reinforcement layers is not a linear relation of a function of progressive collapse.