A nondestructive experimental technique for determination of structural flaws in cantilever beams is presented. The proposed
method is capable of detecting location of cracks and other possible structural flows on a beam using its natural frequencies
and vibration mode shapes measured on a roving mass on the beam. To verify the validity of the proposed method,
vibration response of a cracked cantilever beam with a stationary roving mass is investigated. The beam is modeled as an
Euler-Bernoulli beam with rectangular cross section. The axial and transverse deformations of the cracked beam are coupled
through a stiffness matrix determined using the fracture mechanics principles. The developed model is used to determine
analytical solutions for the variation of natural frequencies and mode shapes of a cracked cantilever beam versus the position
of the roving mass. The analysis indicates that the variation of the natural frequencies versus position of the roving mass can
drastically change when the roving mass is close to the position of a flaw. Moreover, the effects of the location and depth of
the crack, the location and the weight of the roving mass on the natural frequencies, and mode shapes of the beam are investigated.
The analytical results show that the coupling between the axial and transverse vibrations for moderate values of crack
depth and/or roving mass is weak. Increasing the crack depth, the mass and the rotary inertia increases the coupling effect.
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