ELECTRO-MAGNETO-ELASTIC ANALYSIS OF A PIEZOELECTROMAGNETIC STRIP WITH A FINITE CRACK UNDER LONGITUDINAL SHEAR

The singular stress,electric and magnetic fields in a piezoelectromagnetic strip containing a Griffith crack under longitudinal shear are obtained by the theory of linear piezoelectromagneticity.The crack is situated symmetrically and oriented in a direction parallel to the edges of the strip,which is assumed to be permeable.Fourier transforms are used to reduce the mixed boundary value problems of the crack to dual integral equations.The solution of the dual integral equations is then expressed in terms of Fredholm integral equations of the second kind.Closed forms of the stress,strain,electric displacement,electric field,magnetic field,and magnetic induction in the vicinity of the crack tip are derived by the use of asymptotic expansion.It is shown that,for the permeable crack,the electric field intensity factor(EFIF)and the magnetic field intensity factor(MFIF)are always zero;the width of the strip has significant influence on the stress intensity factors.The energy release rate is always positive.