Vibration of Open Thin-Walled Beams with a Breathing Crack

F.E. DOTTI; V.H. CORTINEZ

Buzios

Simposio; DINAME 2013 - Proceedings of the XV International Symposium on Dynamic Problems of Mechanics; 2013

Asociación Brasilera de Mecánica Computacional (ABCM)

The presence of damage in structural elements represents a critical issue in their security. With regard to engineering structures, the most common damage corresponds to cracks associated to material fatigue. In its modelation, cracks are often considered as completely open, that is, a linear model. As a matter of fact, this linear crack is considered in most of the scientific work available in literature. But in the case of fatigue cracks, it is more realistic to consider that cracks may be open or closed during the motion. This effect, known as ?breathing?, depends on the nature of the flaw itself, the type of loading and the vibration amplitudes. In order to study this effect, it is required to solve a non-linear dynamic problem. In this paper, the dynamic behavior of thin-walled beams with the presence of a breathing crack is studied. It is shown that, because of the non-linearity of the crack, effects appear in the system whose presence is impossible if the crack is considered completely open. Among the mentioned effects, self excitation of both sub-harmonic and super-harmonic resonances can be highlighted, as also the presence of period doubling in the phase plane.