Damage evaluation via flexibility formulation

The feasibility of estimating structural damage using a formulation of the element flexibilities is examined. A system of sensitivity equations is generated from the physical parameters of the structural elements of an initial structure and from measured modal parameters of the damaged structure. As opposed to previous methods, the formulation does not rely on element stiffnesses but rather on element flexibilities. A special algorithm is used to reason from the contribution of the flexibility of the structural members to the sensitivities of the modal parameters to changes on the flexibilities of the members. A numerical experiment on a mechanical system with elastic truss members as well as elastic joints is performed to validate the approach. Modal parameters of the damaged structure are computed vial solving the general eigenvalue problem. Knowing only the modal response and the physical parameters of the initial structure, the theory is used to recapture the damage in the structure. The results demonstrate excellent agreement between the prediction and the simulation.