Delamination Detection of a Laminated Beam Using Magnetostrictive Composite Sensor and Actuator

Abstract

This article presents an analytical dynamic model to study the feasibility of sensing a delamination embedded in a cantilever laminated composite beam, which is bonded with an integrated or distributed magnetostrictive layer. The model that includes parameters characterizing a delamination is developed using the classical beam theory and the assumption of constant peel and shear strains through the bond line thickness. A movable sensing and actuation coil is employed to excite the beam system and then to measure the magnetic flux passing through the sensing and actuation coil. Two types of moveable sensing and actuation coil, namely integrated sensing and actuation coil and separated sensing and actuation coil, are introduced in this investigation. Using the present model, the magnetic flux passing through the coil is predicted. Thus, by monitoring the difference of the predicted magnetic flux passing through the coils which encircles the beams with and without a delamination, the presence, location, and size of the delamination embedded in a laminated composite beam will be identified. Finally, a numerical study is conducted to investigate the influence of major parameters on delamination detection sensitivity, and a comparison of the first- and third-order frequencies between the present analytical and finite element analysis models is carried out to verify the present analytical model.