【摘要】 模型修正即为利用模态测量数据修正存在但不准确的有限元模型。在假定有限元模型的质量矩阵与刚度矩阵均为对称非负定矩阵,并且质量矩阵是精确的情况下,提出了一种修正刚度矩阵的新方法。该方法借助于矩阵的Kronecker积与拉直算子,把需修正的变量分离出来直接对其进行修正,得到了满足特征方程与正交性条件的最逼近有限元刚度矩阵的唯一修正矩阵。该方法不仅保证了修正矩阵带状稀疏的特点,而且修正过程简单易行。数值例子验证了该方法的有效性。更多还原

【Abstract】 A new updating method for stiffness matrix was provided under the assumption that the mass matrix and the stiffness matrix of a finite element model are symmetric and semi-positive-definite and the mass matrix is exact.By using the Kronecker product and the stretching function,all the variables to be modified were found out and then updated directly.The optimal approximate stiffness matrix which satisfies the required eigenvalue equation and the orthogonality condition was found under the Frobenius norm sense.The characteristic of sparseness of the updated matrix is preserved and the procedure of the method is very simple and easy to realize.The numerical example shows that the presented method is quite accurate and efficient.更多还原