Reconstruction Method for Damage Detection in Beams Based on Natural Frequency and Antiresonant Frequency Measurements

This paper deals with a dynamic method for damage detection in beams. Under the assumption that the damaged beam is a perturbation of the undamaged one, it is shown that natural frequency and antiresonant frequency shifts induced by structural damage contain information on certain generalized Fourier coefficients of the stiffness variation caused by the degradation. A reconstruction method based on this property is proposed to solve the inverse problem. Cases with pseudoexperimental and experimental data are discussed. The results are in good agreement with the theory, provided that average frequency and antiresonant frequency shifts are bigger than modeling/measurement errors.