交通荷载作用下桥梁结构参数识别方法

应用动力节点加载法,将作用在桥梁上的交通荷载转化为等效节点荷载,再用两步构造法识别结构物理参数.第1步,用Newmark-β方法变换结构运动方程,并用结构的加速度响应求得变换空间内的位移、速度和加速度响应;第2步,基于最小二乘原理,构造出变换空间内求解结构参数的递推式,进行结构物理参数识别.数值模拟结果表明,在交通荷载作用下,该方法能够快速、准确地进行桥梁结构参数识别.

Structural Parameter Identification of Bridge Excited by Traffic Loads

Based on the dynamic nodal loading approach, the traffic load excitation was transformed into the equivalent nodal excitation. Then, the two step identification method was used to identify structural parameters of a bridge. Firstly, the Newmark-β method was employed to transform the equation of struc ture motion, and a new form of motion equation came into being, and the measured acceleration was used to construct the displacement, velocity and acceleration responses in the transformed space. Secondly, the structural parameters were identified using the recurrence formula constructed by the least-square method. The method proposed in this paper offers an efficient approach for bridge structural parameter identifica tion under traffic excitation. The numerical simulation results show that the method can identify the struc tural parameters of a bridge excited by traffic loads accurately and rapidly.