基于ANSYS的小箱梁预应力阶段受力分析

分别建立模拟台座与简支状态ANSYS有限元模型,将计算结果与实测数据对比分析,结果表明:对于20 m小箱梁张拉阶段张拉N1钢束时压应力变化较小,张拉N2钢束时压应力开始迅速增长,N3钢束张拉时增长幅度最大,此时梁体各截面均处于受压状态;采用Link10单元模拟台座可以准确的反映自重参与受力的情况,通过与简支模型对比,梁体自重自N2钢束张拉开始逐渐参与梁体受力,直至钢束全部张拉完,自重全部参与梁体受力,因此在工程上当不需要张拉阶段的梁体应力时,可直接采用无支撑模型计算张拉完成时的应力状态。

The analysis of small box girder in prestressed stage based on ANSYS

Establishing the model with pedestal and simply supported ANSYS finite element model, and contrasting the measured data with AN- SYS finite element model. The results show that the compressive stress changes little when N1 stand is tensioned for 20 m small box girder, it changes quickly during the tension of N2 stand, and the increase of stress is largest when N3 stand is tensioned, every cross-section of the small box girder is in compression during this time. The case of the weight participating the force for the girder can be accurately reflected across the model with pedestal simulated by LinklO element, the weight begin to participate in the force of girder from the tension of N2 stand by comparison with the simply supported model, until all of the stand ale tensioned, the weight totally participate in the force of girder. Therefore the model without support can be used directly to calculate the stress of the small box girder when the stress is unusefull during the stage of prestressing in engineering.