Investigation into Mass, Stiffness and Damping Matrix Updating by Error Matrix Method

The paper essentially deals with the error location in spatial matrices (mass, stiffness and damping) derived by both the numerical and the experimental data. This problem is useful not only in the damage location, structural ageing, and in general in the structural reliability, but also and above all for the updating process of the matrices mentioned above. As it is not possible to use complete models, the effects due to the number and to the type (low or high frequency) of modes considered in the error location, have been studied. From the numerical tests, relative to a cantilever beam, represented with a 20-DOF finite element model and with the structural-proportional damping, even a qualitative evaluation of the error location problem shows the difficulties in the selection of the modes necessary in order to get good location results for spatial matrix updating.