A piecewise constant level set method for damage identification of continuum structures based on natural frequencies

The damage identification of continuum structures from the observation of its natural frequencies is investigated. The piecewise constant level set (PCLS) method is applied to represent the shape and topology of the damaged region. The functional derivative of the objective function with respect to PCLS function is derived with the application of the continuum sensitivity analysis. A regularized restarted conjugate gradient algorithm is proposed. Identifications of single and multiple damaged regions in 2D cantilever structures are discussed, illustrating the validity of the proposed algorithm.