Nonlinear vibration characteristics analysis of a cantilever beam with slant crack

Aiming to investigate the slant crack fault of a cantilever bar or beam, this paper analyzes the nonlinear dynamic characteristics of a cantilever beam with a slant crack based on ANSYS software. Assuming that only a bending vibration of the cantilever beam is considered, a finite element (FE) model is established using mixed elements. In the model, the plane elements (Plane 183) are adopted in the crack region and the contact elements are used to simulate the breathing effect of the slant crack. Moreover, beam elements are utilized in the regions that are far away from the crack region. By comparing this with the FE model composed by full plane elements, the accuracy of the developed model is verified; in addition, the calculation efficiency is evaluated. Finally, the effects of crack angles and the amplitude of the excitation force on the vibration responses of the system are also analyzed. The results show that the nonlinear characteristics caused by a slant crack are more obvious with the increasing crack angles. Among the vibration responses, the amplitudes of the base frequency and its multiple frequencies have a linear relationship with the amplitudes of the excitation force.