Vibration Analysis of a Cracked Cantilever Flat Plate

Abstract

This paper investigates the opportunities of observing the response of a cantilevered flat plate through vibration analysis using Eddy-Current Displacement sensors. External disturbance such as excitations, fluctuating loads etc. in plates causes vibration problem. Coupled bending and torsional motion is found in vibration analysis of cantilevered flat plates. It has been observed previously that with the increase in crack or slit length, natural frequency of a plate structure decreases. Here, non-linear vibration response for different crack position and length are to be inspected in relevance with similar works of other authors and also using finite element method for cross verification. Eddy-Current displacement sensors are used for measuring very small changes in displacement. Different types of root-slit are inspected numerically and experimentally. The output from the sensor are compared with available data. The linear free vibration response of cracked flat plate is measured using FEM calculation. The veering seen in between the higher modes of different crack models are also assessed. Errors found in the finite element analysis is also corrected and pointed out. The results validate the use of eddy-current displacement sensors in addition with the possibility of using FEM calculations for crack detection in a given structure.