实验模态数据修正计算模型的改进拉直算法

An improved straightened algorithm for modification of calculation model with experimental mode data

针对实验模态数据修正计算模型拉直算法存在的缺陷,提出了一种改进拉直算法:首先通过拉直方法,把待修正的质量和刚度矩阵的方程变为线性方程;然后把位于质量和刚度矩阵带状内的元素限制在给定范围内,并运用优化和迭代方法确定修正模型.该算法还考虑了带状矩阵内存在部分值为0的情况.实例计算结果表明,采用改进拉直算法,可以缩小修正模型质量阵和刚度阵与原模型质量阵和刚度阵之间的差别,使修正模型更符合实际,精度也很高.

In consideration of some defects in the original straightened algorithm, an improved straightened algorithm was put forward. Firstly, the equations for mass and stiffness matrices were changed into linear ones by the straightened method; then the elements within the mass and stiffness band matrices were limited to a certain range, and the modified model was obtained by use of the optimization and iteration method. In this algorithm, the case of partial elements in band matrices being zero was also taken into account. The calculated result from case study shows that the improved straightened algorithm is helpful to decrease the differences between the mass matrices and stiffness matrices of the modified model and original model, and makes the modified model closer to the reality, and thus, high precision of the modified model could be obtained.