6Raju I S, Newman JC. Stress-intensity factors for a wide range of semi-elliptical surface cracks in finite-thickness plates [ J ]. Engineering fracture mechanics, 1979, 11 (2) : 817-829.
7Aliabadi M H. Boundary element formulations in fracture mechanics[J]. ApplMech Rev, 1997, 50(2) :83-96.