基于模态价值分析的结构动力学模型降阶

针对小阻尼和无阻尼结构，提出了一种模态价值分析方法，用于在模态坐标下的动力学模型降阶问题。在得到系统动力学方程的基础上，首先进行模态分析，然后由模态参数和系统的输入输出矩阵计算各模态的价值，最后选择若干价值最大的模态向量形成变换矩阵对系统进行降阶。通过两个算例说明本文方法是对通常选择低频模态的降阶方法的改进，提高了低阶模型的精度。

ORDER REDUCTION FOR STRUCTURAL DYNAMIC MODEL USING MODAL VALUE ANALYSIS

A modal value analysis method is presented to obtain a reduced-order dynamic model with modal coordinates for structures with small damping or without damping. Giving the full order dynamic model or a structural system,modal analysis is carrid out firstrly.Net,the value of each mode is calculated using modal parameters and input and output matries.Finally,the modal vectors with relative high value are selected to form a transformation matrix used in model reduction.Two examples are given to show that order reduction technique based on modal value analysis method is superior to the common technique which simply selects the modal vecors associated with the lower modal frequencies.