The stress cracking property was evaluated using the NCLS test, and the test data were subsequently analyzed using the

stress intensity factor K and the J-integral.

Handbook of the

stress intensity factor, Revised edition.

This is the location where a crack was introduced to give the largest

stress intensity factor (KI).

Soltani, "Analysis of effective parameters for

stress intensity factors in the contact problem between an asymmetric wedge and a half-plane using an experimental method of photoelasticity," Materials and Design, vol.

For the fatigue crack growth simulation in Regime III, the constant loading amplitude is applied with [F.sub.max] = 24 kN at R = 0.1, which corresponds to the initial

stress intensity factor range [DELTA] [K.sub.i] = 76 MPa [m.sup.1/2].

The whole

stress intensity factor of breakdown pressure is divided into three parts: [K.sub.1] is the

stress intensity factor of in situ stress; [K.sub.2] is the

stress intensity factor of borehole stress; and [K.sub.3] is the

stress intensity factor in pore stress.

It will help to release (10) and to calculate later the

Stress Intensity Factor (KI) as stated in (13).

Averaging all the results of the tests, critical value of

stress intensity factor [K.sub.Ic] is about 6.76 MPa[square root]m for CT specimens.

The

stress intensity factor of Mode II for the double notch four-point beam due to the external load P, is given by (Guryao, 1996) (Equation 8):

Analytical

stress intensity factor solutions for continuous welds in lap-shear specimens with idealized weld geometries were presented in Amodeo and Pan [15].

Table 1 gives normalized

stress intensity factors [Y.sub.I] = [K.sub.I]/[sigma][square root of ([pi]a)] for various numbers of nodes collocated on crack surface.

The

stress intensity factors [K.sub.I] and [K.sub.II] at the crack tip can be used to obtain the geometric correction factors [F.sub.I[theta]](a/h) and [F.sub.II[theta]](a/h).