移动荷载识别的函数逼近法

由多式函数，三角函数及其结合逼近桥梁挠度，对逼近函数分求得桥梁挠曲速度和加速度，用最小二乘法由桥梁挠度及近似的挠曲速度和加速度识别桥梁的模态位移、模态速度和模态加速度，由梁的模态座标方程和最小二乘法识别上移动荷载。与以前的识别方法相比，函数逼近的识别方法受测量噪声的影响较小。

FUNCTION APPROACHING METHOD IN MOVING LOAD IDENTIFICATION

The polynomial function,trigonometric function and their combination are used to approach the deflection of bridge.The vibration velocity and acceleration of the bridge are approached by the first and second derivatives of the functions.The modal displacements,velocities and accelerations of the bridge are obtained from the deflection,approached velocity and acceleration of the bridge by using the least square method.The moving loads on the bridge are identified with the least square method based on the modal coordinate equation of the bridge.The identification results are less sensitive to measurement noise by using the function approaching method,comparing with the previous method.