Mechanical Impedance of a Cracked Cantilever Beam

Abstract

In this paper the influence of a transverse surface crack on the mechanical impedance of a cantilever beam is investigated both analytically and experimentally. Modeling the flexibility induced by the crack by a linear spring constant, relations linking the changes of the mechanical impedance to the location and size of the crack are obtained for both longitudinal and flexural vibrations. The results show that the mechanical impedance changes substantially due to the presence of the crack in case of flexural vibrations. The changes follow definite trends depending upon the location and size of the crack and consequently the impedance can be used as an additional defect information carrier for crack appearance and possible estimation of crack location.