中文摘要：

以体外预应力简支梁为例，讨论了预应力梁的振动过程中预加力的变化情况，建立了梁的受力模型，导出了预应力梁横向弯曲振动的微分方程．采用模态摄动法，得出求解预应力梁的动力特性的近似求解方法．通过算例结果和实验数据的比较，验证了算法的准确性．

英文摘要：

Based on the study of a simply-supported prestressed beam, the changes of the preloading in the vibration process of the beam are discussed and the analysis model of the beam is established. As a result, the differential equation of the lateral vibration for the simply-supported prestressed beam is obtained. The mode perturbation method is applied to deduce the approximation analysis technique for dynamic characteristics of the prestressed beam. The accuracy of the method is verified by the compariron of the results of a numerical example with the experimental data.