APPENDIX
 STRESS SINGULARITY USING STROH'S METHOD

 Stress singularity at a ply crack tip acting normal to an interface of composite

laminates can be obtained using Stroh's method. The displacements ui (i=1,2,3) are in the

xi-x2 plane as shown in Figure A. 1.
















Figure A. 1.Geometry of an angle-ply laminated composite and a crack normal to an
 interface between two anisotropic materials.


 The strains and the stresses are described as a function of x2 and x3. The

displacement, stress-strain and equilibrium equations can be written as

 E, = (0u, x + a uj ax)/2 (Al)

 Cl = Cijkp.- (A2)






A1-A3 can be obtained by letting
A1-A3 can be obtained by letting