基于分段思想的变截面连续梁桥动力特性计算

Calculation method of the dynamic characteristics of continuous beam bridge with variable cross-section based on staging concept

对连续梁桥的每一跨进行分段,采用待定系数表示每一段的振型函数,并且依据段间的连续条件建立每一跨内待定系数的传递方程。依据全部边界条件和传递方程,形成全桥待定系数的求解方程,通过对待定系数方程的求解便可计算出桥梁的自振频率和振型。最后,采用该方法对一座连续梁桥的动力特性进行求解,验证了该方法的有效性和可靠性。

A calculation method of the dynamic characteristics of continuous beam bridge with variable cross-section is proposed based staging concept.In this method,each cross of a girder bridge is segmented;the undetermined coefficients are used to express the vibration mode function of each segment;the transfer equations within the undetermined coefficients of each cross are established based on intersegmental continuity condition. The equations of the full-bridge undetermined coefficients are formed based on all the boundary conditions and transfer equations.The method is able to calculate the natural frequency and vibration mode of the bridge by solving the equations of undetermined coefficients.This method is applied to solve the dynamic characteristics of a continuous box girder bridge to demonstrate its validity and reliability.