THE EFFECT OF SECOND AXIAL FORCE ON BEARING CAPACITY OF PRESTRESSED CONCRETE FRAME

With a bearing capacity test on prestressed concrete frame, the frame is simulated by finite element software ABAQUS.The simulation results agree well with the test results.Based on this, three sets of finite element models are set up.By changing the boundary conditions, the analysis is carried out.The results show that the existence of the secondry force reduces the ultimate resisting moment.Under different prestress-degree, reinforcement ratio, tension control stress and initial secondry force, the secondry force is smaller than the initial force with formation of a plastic hinge in the beam end, but its value should be still large.So the effect of the secondary axial force should be considered in calculation of bearing capacity.