For a 3-D crack under impact loading, dynamic J-integral method, which is independent of the domain used and robust even with coarse meshes, is used to calculate the dynamic stress intensity factor
(SIF) along the crack front in this study.
Calculation of the Stress Intensity Factor
. For the uniform transparent plate specimen normal to the object wave principle axis, the relationship between the stress and phase difference of the object wave in plane stress state can be expressed as 
One of the extensively used models for predicting fatigue crack growth is the Paris' law  which relates the range of the stress intensity factor
[DELTA]K and the crack growth rate da/dN through a power law in double logarithmic coordinates.
The stress intensity factor
is positively correlated with the pore pressure .
The literature highlights the existence of some methods based on the Stress Intensity Factor
(KI) concept that permits evaluating with accuracy the fracture of the structures.
Parameters used for characterizing fracture behavior that are derived in the framework of fracture mechanics are: 1.) pre-exponent and exponent of the Paris curve that is used to describe fatigue crack growth rates; 2.) fracture toughness in the linear elastic and elastic-plastic fracture mechanics regimes based on the stress intensity factor
(K) and the energy parameter J-integral; and 3.) tearing modulus (T) defined as the slope of the J-resistance curve for ductile fracture.
where: B is the specimen thickness, a is the crack length, W is the specimen width, [K.sub.Q] is the stress intensity factor
value corresponding to the [P.sub.Q], and [[sigma].sub.y] is the yield stress.
This coefficient is called stress intensity factor
. The LEFM converts stress to a unique form of distribution.
but the BCP reached the highest critical stress intensity factor
range [DELTA][K.sub.Ic] without compromising the glass transition temperature.
Niu and Glinka  investigated the effect of weld geometry on the stress intensity factor
solutions for welded T-butt joints under a variety of loading conditions.
Gross, "A hyper-singular traction boundary integral equation method for stress intensity factor
computation in a finite cracked body," Engineering Analysis with Boundary Elements, vol.
Xiaocui, "XFEM analysis of the effects of voids, inclusions, and other cracks on the dynamic stress intensity factor
of a major crack," Fatigue & Fracture of Engineering Materials Structures, vol.