建立了预应力混凝土箱梁模型在重复荷载作用下纤维分析模型,并展开非线性力学反应分析。对纤维模型的截面特征、非线性材料本构关系的选择等各项关键技术进行了论述。计算结果表明:有限元计算得到荷载位移滞回曲线与试验结果吻合良好,纤维模型法能够较好地预测高速铁路预应力混凝土箱梁整个加载历史的非线性结构响应。 The fiber analysis model of prestressed concrete box girder under repeated load was established and the nonlinear mechanical response analysis was carried out. The key features of the cross-section of the fiber model and the constitutive relation of nonlinear materials are discussed. The calculation results show that the load-displacement hysteretic curve calculated by the finite element method is in good agreement with the experimental results. The fiber model method can predict the nonlinear structural response of the whole loading history of high speed railway prestressed concrete box girder.