Nonlinear Finite Element Analysis On Torsional Stiffness Of Steel Reinforced Concrete Structures

Steel reinforced concrete structure is a new type of composite structure formed by adding steel in the reinforced concrete.Bone,steel bar and concrete formation of the force of the community to give full play to their strengths.Compared with reinforced concrete structures and steel structures.Compared with reinforced concrete structure and steel structure,steel reinforced concrete structure has the advantages of strong seismic performance,high bearing capacity,good corrosion resistance,large rigidity and simple construction,so the structure can be gradually applied to the actual engineering construction in the world.In foreign,there are few theoretical studies on the torsion of steel reinforced concrete structures.In the actual project there are still many problems have not been resolved and improved.China has entered the rapid development stage of steel reinforced concrete structure application and research.There are two specifications for the construction of steel reinforced concrete structures now,namely,"Technical Specification of Steel Reinforced Concrete Structures "(YB9082-2006)and " Technical Specification for steel reinforced concrete composite structures "(JGJ138-2001).In the actual project,the torsional failure of steel reinforced concrete structures is more common,but there are few specifications for the torsional behavior and calculation methods of steel reinforced concrete members.So in the application,there are many adverse effects.This paper is simulated by ABAQUS finite element software,And study on the variation law and calculation formula of torsional stiffness of tensile member of steel reinforced concrete members.This paper will study the reinforced concrete composite torsion members from the following three directions:(1)This paper is based on finite element software ABAQUS,determining the constitutive relationship of the material,the principles of the software and the parameters required for modeling.ABAQUS finite element software was used to simulate a steel reinforced concrete member of National Central University.To verify the validity and accuracy of the ABAQUS finite element model,This paper analysis and comparison of simulation results and test conclusions of torque-torsional curve,cracking torque limiting Torque and so on.(2)This paper analyzes the stress-strain relationship between reinforced concrete members and steel reinforced concrete members.And compared and analyzed under the bending and twisting of reinforced concrete members and six reinforced concrete members,it is found that the torsional rigidity of the components is improved at different stages,such as steel configuration,axial compression ratio,reinforcement ratio and steel content.(3)The simplified treatment of Torque-Torsion rate curve of steel reinforced concrete pressure bending and torsion members.The whole process of the member’s torsion is divided into three stages according to the crack and yield of the member.Taking the result of Abaqus finite element as data source,based on the theory of stiffness superposition and space truss model,considering the effect of axial compression ratio on the torsional stiffness of steel bar and concrete before cracking,the influence coefficient of axial compression ratio and the correction coefficient of section stiffness of section steel are added.In this paper,the formulas of torsional stiffness of steel reinforced concrete members under various stages are proposed creatively.