Abstract：Model updating concerns the modification of an existing but inaccurate finite element model with measured data. In this paper, a new updating method for the stiffness matrix is established under the assumption that the mass matrix and the stiffness matrix of a finite element model are symmetric positive semi-definite and the mass matrix is exact. By using the Kronecker product and the stretching function, all the variables to be modified can be found out and then are updated directly. The optimal approximation stiffness matrix which satisfies the required eigenvalue equation and orthogonality condition is found under the Frobenius norm sense. The sparse characteristic of the updated matrix is preserved and the procedure of this method is very simple and easy to realize. The numerical example shows that the presented method is quite accurate and efficient.
2009, Vol. 28 
