【摘要】 用预应力梁-杆组合结构模拟体外预应力梁,以体外预应力简支梁为例,建立了预应力梁杆单元动力刚度矩阵。采用动力刚度法,进一步推导出预应力梁-杆组合结构的整体动力刚度矩阵,利用Williams-Wittrick算法求解频率。本文以理论推导为基础,引入了动力刚度法。最后通过算例,讨论了各种因素对梁横向的振动特性的影响,并与试验值比较。计算结果表明:动力刚度法能够精确有效的求解体外预应力混凝土梁的横向振动问题。更多还原

【Abstract】 A prestressed beam-bar composite structure model was introduced to simulate an external prestressed beam.A simply-supported external prestressed beam was studied.The dynamic stiffness matrix method was used to establish the element and the global dynamic stiffness matrices for the beam-bar composite structure model of the external prestressed beam.As a result,the frequency solution was obtained by means of Williams-Wittrick algorithm.Based on the theoretical derivation,the dynamic stiffness method was introduced.The influence on the natural frequencies of the beam were also discussed.Numerical results showed that the dynamic stiffness matrix method is reliable,efficient,and well applicable to this kind of problems.更多还原