中文摘要：

针对PC简支梁结构，对目前主要研究成果进行了分析和评价。通过PC简支梁试验对预应力影响自振频率的全过程进行了分析。PC简支梁的预应力对频率的影响分为前后两个阶段，随着预应力的不断增加，自振频率由前期的增加转入后期的下降，两者之间并非单调增加或减小的关系。将预应力等效为施加在梁端的外力，其力学模型是不正确的。对于匀质没有开裂的理想预应力混凝土梁，理论上，自振频率与预应力无关，因此，预应力主要是通过使混凝土材料内微裂纹等损伤状态的改变影响自振频率。

英文摘要：

This paper summarizes current main structures. Effect of prestress on the natural research achievements focusing frequency during the whole on PC simple supported beam process is analyzed through experimental study on PC simple supported beams. The effect of prestress on frequency of PC simple supported beams can be divided into two stages, where natural frequency increases as the prestress increases during the first stage, and the opposite for the second stage. Mechanical models simplifying the prestress as equivalent external forces at the beam ends are not correct. For a homogeneous uncracked ideal PC beam, natural frequency is theoretically hardly affected by the prestress. Thus, the influence of the prestress on the natural frequency is mainly induced through damage such as internal micro-cracks.