Abstract
The crack position in a cantilever beam is identified. The vibration experiment is conducted and the eigenfrequency data is obtained by measuring the acceleration of the beam tip. The extended finite element method is used to analyze the vibration problem. The evaluation function is calculated using the eigenvalues of both experimental and numerical simulation, and the identification is conducted based on the gradient of the evaluation function. The accuracy of longitudinal direction is much more higher than that of thickness direction. That difference is caused by the characteristic distribution of eigenvalues.