“…Problems with Griffith cracks in orthotropic elastic materials were considered by Erdogan et al [7], Dhaliwal [6], Satpathy and Parhi [18], Piva and Viola [13], Cinar and Erdogan [3], Lowengrub and Srivastava [11], De and Patra [5], Kassir and Tse [9], and others. Analytical studies of crack interaction problems can be found in Sneddon and Lowengrub [19], Rose [14], Lam et al [10], Brencich and Carpinteri [1], Chudnovsky and Kachanov [2], Rubinstein [16], Horii and Nasser [8], and so forth.…”