Abstract: In this paper a method based on a line-spring model was proposed to analyze approximately vibration responses of cracked beams. The method in conjumction with the Euler-Bernoulli beam theory. modal analysis and fracture mechanics principle was applied to derive a characteristic equation for the cracked beam vibration. As application examples. natural frequency responses for a cracked hinge-hinged beam and a cracked cantilever beam were examined It was shown that the present solutions obtained are quite in agreement with the solutions or experimental results in available references.

Key words: cracked beam, line-spring model, response of natural frequency