Analysis On Stress Of Unbonded Prestressed Beam And Wall During The Process Of Tension

Pre-stressed concrete technology shall be such a mature building construction technology that has been applied widely,it does not significantly reinforce the anti-cracking performance of the structure parts,but also effectively improve the rigidity of structure parts.The stretching process of prestress shall be the precondition for performing all excellent performances,it determined the effect of prestress inside structure parts,so that the stretching process of pre-stressed concrete bars shall be very important,the field monitoring shall be the effective channel to understand the change of the stress it was burdened.Thus in this paper,through using the finite element analysis MIDAS GEN it makes the finite element simulation on the prestress stretching process of the beam and wall in actual engineering,and also makes the comparative analysis by combining the measured data.The main content of such study are given below:(1)By using MIDAS GEN to establish the pre-stressed beam model,by using the solid strand method and solid reinforcement method respectively to put the pre-stressed load on the beam,and then to make the comparative analysis on both the simulated analysis result and the tested experimental data during the prestress stretching process on spot.The result shows that: in comparison with solid strand method,the simulated result that puting the prestress by using solid strand method shall be more closer to the measured data.(2)By using MIDAS GEN to simulate and analyze the influence of different stretching conditions on the stress of beam body,lateral bending value and inverted arch value.The result shows that,the different stretching conditions may have large influence on the stress of beam body during the stretching process,but has quite little influence on the final stress of the beam body;the different stretching conditions may have the larger influence on the lateral bending value of the beam body during stretching process,and have quite little influence on the final lateral bending value of the beam body,during the stretching process,the maximum lateral bending values under the stretching condition 2 and 3 are respectively 2.07 mm and 12.17mm;the final inverted arch values of the beam body under different stretching conditions may be different,the final inverted arch values under the stretching condition 1,2 and 3 are respectively 8.04 mm,7.63 mm,7.45 mm.(3)By using MIDAS GEN to establish the pre-stressed concrete wall model,and also make the comparative analysis on both the simulated analysis result and detected experimental data during the prestress stretching process on spot.The result shows that,the simulated result with finite element method relatively correspond to the measured data.(4)By using MIDAS GEN to simulate and analyze the influence of different stretching conditions on the concrete wall's stress.The result show that,during the stretching period,different stretching conditions may have the larger influence on the stress of the concrete wall's top part,and have quite small influence on the stress of the concrete wall's middle part.