The Effect Of Post Tensioned Prestressed RC Beam On The Internal Forces Of The Frame Column

In recent years, with the vigorous promotion of prestressed technology, the prestressed concrete structure has been rapid development in the field of civil engineering in our country. The prestressed concrete frame structure which has large bay, large space, good structural integrity, crack resistance and better economic performance has become an extremely important form of building structures. Focusing on the prestressed concrete frame structure, a lot of theoretical analysis and experimental research have been done both at home and abroad. However, In prestressed tensioning construction stage and the use stage, the effect of prestressing force on the internal forces of the frame structure remained to be further discussed. In this paper, theoretical analysis about the effect of post tensioned prestressed beam on the internal forces of the frame column has been carried on in the post-tensioned bonded prestressed concrete frame structure.Firstly, this paper described the theoretical basis of analysis of prestressed concrete structures by ABAQUS analysis. This part included the selection of concrete units, steel units and the constraints, the implement method of prestressed, material model, constitutive relations and the basic method to solve problems of nonlinear analysis of ABAQUS.Secondly, Taking post-tensioned bonded prestressed concrete frame structure as the object of study, the calculation formula of additional bending moment (the third moment) of columns was derived in prestressed tensioning construction stage. Then modeling analysis of different prestressed concrete frame structures has been created by ABAQUS analysis. It was shown that internal forces of the frame structure by tensioning prestressed tendon were affected by beam-column stiffness ratio, number of spans, and tensioning construction schemes.Finally, gravity second-order effect of frame column in use affected by prestressing force was analyzed. The analysis of a reinforced concrete frame structure has been completed by SAP2000finite element analysis software. Difference of calculation results about gravity second-order effect has been obtained between " Code for Design of Concrete Structures "(GB50010-2010) and " Technical Specification for Concrete Structures of Tall Building "(JGJ3-2010). Considering number of spans and reinforcement percentage of prestressing tendons, lateral displacement and moment of columns in use affected by gravity second-order effect has been studied. At last, it was provided that design suggestions and structural measures to reduce the effect of the prestressing force on internal forces.