Dynamic singular moments in a perfectly conducting mindlin plate with a through crack under a magnetic field

Following Mindlin's theory of plate bending of magnetoelasticity, we consid er the scattering of time-harmonic flexural waves by a through crack in a p erfectly conducting plate under a uniform magnetic field normal to the crac k surface. An incident wave giving rise to moments symmetric about the crac k plane is applied. It is assumed that the plate has the electric and magne tic permeabilities of the free space. By the use of Fourier transforms we r educe the problem to solving a pair of dual integral equations. The solutio n of the dual integral equations is then expressed in terms of a Fredholm i ntegral equation of the second kind. The dynamic moment intensity factor ve rsus frequency is computed and the influence of the magnetic field on the n ormalized values is displayed graphically. It is found that the existence o f the magnetic field produces lower singular moments near the crack tip.