基于随机激励响应的参数识别相关函数法

Correlation Function Method for Parameter IdentificationBased on Random Excitation Response

以桥梁节段模型风洞试验为工程背景,建立桥梁节段模型的竖向和扭转耦合振动微分方程。风荷载对桥梁的作用可以考虑为气弹阻尼力、气弹刚度以及高斯随机激励力;利用随机振动理论,推导了随机激励下两自由度振动响应的相关函数方程,利用最小二乘法构造参数识别方程。提出了基于随机激励响应的参数识别相关函数法,并用数值模拟方法验证了该方法的有效性,最后将该方法应用于识别风洞试验系统中的刚度矩阵和阻尼矩阵。研究结果表明:在低风速条件下,方法所得结果与自由振动时域识别法获得的结果接近。

Based on the wind tunnel test of bridge sectional model,the differential equations of vertical and torsional coupling vibration of bridge segment model were established.The effect of wind load on bridge could be considered as aero-elastic damping force,aero-elastic stiffness and Gaussian random excitation force.By use of the theory of random vibration,the correlation function equation of two-degree-of-freedom vibration response under random excitation was derived,and the parameter identification equation was constructed by the least square method.The correlation function method for parameter identification based on random excitation response was proposed,and the validity of the proposed method was verified by numerical simulation.Finally,the proposed method was applied to identify the stiffness matrix and damping matrix in wind tunnel test system.The research shows that the results obtained by the proposed method are close to those obtained by the free vibration time domain identification method under low wind speed conditions.