中文摘要：

预应力对结构动力特性的影响可由等效荷载法求解。首先分析了用等效荷载法推导出结构动力平衡方程式,求出一般理论计算解,再用有限元方法给出一般求频率的通用方法。为了反映预应力对整体梁刚度影响,采用弯矩面积相等的方法,求出直线筋、折线筋和曲线筋的等效荷载。再通过对普通梁受直线筋、折线筋和曲线筋荷载效应对结构刚度影响的分析,结果表明：直线筋对频率影响最小,曲线筋次之,折线筋最大。各种线型钢筋对频率阶次的影响,低阶影响较大,高阶影响较小。

英文摘要：

Prestress force impacting on dynamic property can be solved by equivalent force method.To show the prestress effect on frequency,equilibrium equation can be derived.Utilizing finite element method,a common procedure is provided.In order to reflect the prestress effect on the whole beam dynamic property,equilibrium force is calculated for straight bar,fold bar and curved bar by moment area equality method.Through the straight bar,fold bar and curve bar effect on structure frequency,the results show straight line impacts least,curve bar impacts more than straight bar,and fold bar impacts most.Concluding three type prestress bars,prestress force influences the low frequency more than high frequency.