基于附加已知刚度的动力学模型修正方法

A DIRECT MODEL UPDATING METHOD USING ADDED KNOWN STIFFNESS

为了解决模型修正中所需要模态数据不足的问题,提出了一种基于附加已知刚度的模型修正直接方法。通过给原结构添加刚度系数已知的刚度元件来得到一个新结构,进而得到新结构的模态数据,并联合使用原始结构及新结构的模态数据进行模型修正。在所要修正的参数数目一定的情况下,该方法增加了可以用于模型修正的模态数据,大大降低了所需的模态阶数。分别使用一个25自由度质量弹簧系统及一个长直机翼模型的模型修正算例,验证了该方法的有效性和修正精度。

In order to solve the problem of insufficient measured modes in the dynamic model updating, a direct model updating method using added known stiffness components is proposed. In this method, a revised structure is obtained by adding the known stiffness components to the original structure, and then the measured modal parameters of both the original structure and the revised structure are used to update the dynamic model. For a definite set of parameters to be updated, the proposed method can be utilized to increase the number of the modal parameters available in the model updating procedure, thus the orders of the required measured modes can be largely decreased. Two model updating examples for a 25 degree-of-freedom mass-spring model and a straight wing model are demonstrated numerically to verify the feasibility of the updating algorithm. The results show that using the proposed method, good updating accuracy can be achieved with only a few numbers of measured modal parameters.