In this study, a method to detect stiffness and/or mass changes in a plate was suggested by measuring and comparing the dynamic characteristics.
For a convenience, a Finite Element Model was adopted to get eigenvalues and eigenvectors of an original structure.
The Finite Element Model was modified and improved using experimentally obtained dynamic characteristics via sensitivity concept. The so called error matrix was calculated using improved mass and stiffness matrix in Finite Element Model and modal test results. The error matrix was weighted in order to magnify the failure and its location. It was found that the weighted error matrix has more power to identify the failure locations than the ordinary error matrix method.
In order to apply the above suggested technique to large structure, step-by-step method was tried and found that it is also very helpful to locate stiffness and/or mass changes in large structures.
