Open AccessVibration Analysis of Cracked Structures as a Roving Body Passes a Crack Using the Rayleigh-Ritz Method
Author(s) -
Sinniah Ilanko,
Yusuke Mochida,
Julian De Los Rois
Publication year - 2018
Publication title -
epi international journal of engineering
Language(s) - English
Resource type - Journals
eISSN - 2621-0541
pISSN - 2615-5109
DOI - 10.25042/epi-ije.082018.04
Subject(s) - inertia , vibration , structural engineering , rotary inertia , natural frequency , mechanics , moment of inertia , materials science , acoustics , physics , engineering , classical mechanics
The natural frequencies of a cracked plate with a roving mass were computed using the Rayleigh-Ritz Method for various sets of boundary condition. The obtained frequencies exhibit a sudden shift as a roving body crosses a crack. If the crack is only partial and continuity of translation is maintained, then the frequency shift occurs only when the body possesses a rotary inertia. If the crack is a complete one (through thickness) which permits differential translation to occur on either side of the crack, a particle having mass only (translatory inertia) is sufficient to cause a sudden shift. There is no need for a rotary inertia. This is potentially useful in detecting cracks in structures, as it is possible to track the changes in the natural frequencies of a structure as a test body such as a vehicle on a bridge moves and identify points where sudden frequency changes occur.