Study On Internal Force Redistribution Of Box Girder Bridge With Corrugated Steel Webs

Corrugated steel web box-girder bridge is a new type of steel composite structure.This structure of corrugated steel web plate and concrete give full play to their respective features at work,coupled with the use of external prestressing technology,making its mechanical characteristics different from the ordinary prestressed concrete box girder bridge.Based on finite element modeling model beams,the internal force redistribution question has carried on the detailed analysis and calculation.(1)According to previous scholars' research on mechanical characteristics of corrugated steel web plate bridge,summarized the development condition and mechanical characteristics.Also expounded the conception,research and development of the plastic internal force redistribution.And concluded the specification and literature all around the world about the bending moment amplitude modulation method,the calculation of stress increment.(2)Analyzing the Continuous beam to a load from the start to destroy the whole process,then illustrating the working process of the beam's three phases,the internal force redistribution of prestressed concrete continuous beam summarized as two processes.Combined with the method of literature research analysis of the internal force redistribution are summarized,the existing continuous beam internal force redistribution of the research methods include roughly plastic hinge method,variable stiffness method,the whole process of analysis,and the bending moment amplitude modulation method.Factors that affect the internal force redistribution is more,many scholars through experiment combined with theoretical analysis,it is concluded that the main situation,the secondary moment of prestressed concrete produced with crack,plastic hinge,inclined section bearing capacity and limit stress increment of unbonded tendons.(3)In view of the corrugated steel web plate box girder bridge expounds the use of ANSYS software modeling model,selection of unit and material constitutive relation.According to the characteristics of this kind of bridge and simulation purposes,the use of dispersion crack model,is mainly used inthe structure of load displacement curve.Based on APDL language modeling,corrugated steel web plate with a cross beam as an example,gives the modeling procedure command.(4)Set up a separate calculation model of simply supported test beam and carry on the finite element analysis of ultimate bearing state.Discuss corrugated steel web plate beam from the whole process of loading,yielding and failure under concentrated load.Calculated by the finite element results can be seen that the numerical results can reflect greatly three line working characteristics of the corrugated steel web composite beams.List the stress of externally prestressed tendons and midspan deflection data merge them to fitting curve.The results show that the stress increment and midspan deflecti on are straight lines relationship.(5)With the 2×40m continuous beam as model of the beam,ordinary steel reinforcement ratio for variables.Analyzing under concentrated load across the location of the load displacement curve,internal andextemal prestressed load stress of prestressed reinforcement with curve,the qualitative anslysis of ordinary steel reinforcement ratio effect on ultimate bearing capacity of the continuous beam.Analyze the law of internal force redistribution under different reinforcement ratio by the stress of the negative moment region of the load curve.Sections of different reinforcement ratio are given when the externally prestressed tendon stress increment,the midspan deflection data and curves of ordinary steel reinforcement ratio on the stress increment are analyzed.Finally,continuous beam from loading to failure process of the bending moment amplitude modulation factor and the ultimate bearing capacity of the beam model,and bending moment amplitude modulation coefficient decreases with the increase of reinforcement ratio.