The dynamic stress intensity factor for a semi-infinite crack in orthotropic materials with concentrated shear impact loads

2001 ◽  
Vol 38 (8) ◽  
pp. 1265-1280 ◽  
Author(s):  
C.Y. Wang ◽  
C. Rubio-Gonzalez ◽  
J.J. Mason
Keyword(s):  
Stress Intensity Factor ◽  
Stress Intensity ◽  
Intensity Factor ◽  
Dynamic Stress ◽  
Dynamic Stress Intensity Factor ◽  
Orthotropic Materials ◽  
Impact Loads

Response of Finite Cracks in Orthotropic Materials due to Concentrated Impact Shear Loads

1999 ◽  
Vol 66 (2) ◽  
pp. 485-491 ◽  
Author(s):  
C. Rubio-Gonzalez ◽  
J. J. Mason
Keyword(s):  
Stress Intensity Factor ◽  
Stress Intensity ◽  
Intensity Factor ◽  
Laplace Transform ◽  
Dynamic Stress ◽  
Dynamic Stress Intensity Factor ◽  
Shear Loading ◽  
Orthotropic Materials ◽  
Plane Shear ◽  
Shear Loads

The elastodynamic response of an infinite orthotropic material with a finite crack under concentrated in-plane shear loads is examined. A solution for the stress intensity factor history around the crack tips is found. Laplace and Fourier transforms are employed to solve the equations of motion leading to a Fredholm integral equation on the Laplace transform domain. The dynamic stress intensity factor history can be computed by numerical Laplace transform inversion of the solution of the Fredholm equation. Numerical values of the dynamic stress intensity factor history for several example materials are obtained. The results differ from mode I in that there is heavy dependence upon the material constants. This solution can be used as a Green's function to solve dynamic problems involving finite cracks and in-plane shear loading.

Dynamic Stress Intensity Factor Due to Concentrated Loads on Semi-Infinite Cracks in Orthotropic Materials

2000 ◽  
Author(s):  
C. Rubio-Gonzalez ◽  
C.-Y. Wang ◽  
J. J. Mason
Keyword(s):  
Stress Intensity Factor ◽  
Stress Intensity ◽  
Intensity Factor ◽  
Dynamic Stress ◽  
Fourier Transforms ◽  
Asymptotic Expression ◽  
Dynamic Stress Intensity Factor ◽  
Crack Tip ◽  
Orthotropic Materials ◽  
Isotropic Case

Abstract The transient elastodynamic response due to concentrated normal or shear impact loads on the faces of a semi-infinite crack in orthotropic materials is examined. Solution for the stress intensity factor history around the crack tip is found. Laplace and Fourier transforms together with the Wiener-Hopf technique are employed to solve the equations of motion in terms of displacements. An asymptotic expression for the stress near the crack tip is analyzed which leads to the dynamic stress intensity factor in modes I and II. Similar to the isotropic case, it is found that the stress intensity factor has a singularity and discontinuity when the Rayleigh wave emitted from the load arrives at the crack tip. Results are presented for a typical orthotropic material.

The Dynamic Stress Intensity Factor Due to Arbitrary Screw Dislocation Motion

1983 ◽  
Vol 50 (2) ◽  
pp. 383-389 ◽  
Author(s):  
L. M. Brock
Keyword(s):  
Stress Intensity Factor ◽  
Stress Intensity ◽  
Intensity Factor ◽  
Plane Wave ◽  
Screw Dislocation ◽  
Dynamic Stress ◽  
Critical Level ◽  
Dynamic Stress Intensity Factor ◽  
Dislocation Motion ◽  
Crack Edge

The dynamic stress intensity factor for a stationary semi-infinite crack due to the motion of a screw dislocation is obtained analytically. The dislocation position, orientation, and speed are largely arbitrary. However, a dislocation traveling toward the crack surface is assumed to arrest upon arrival. It is found that discontinuities in speed and a nonsmooth path may cause discontinuities in the intensity factor and that dislocation arrest at any point causes the intensity factor to instantaneously assume a static value. Morever, explicit dependence on speed and orientation vanish when the dislocation moves directly toward or away from the crack edge. The results are applied to antiplane shear wave diffraction at the crack edge. For an incident step-stress plane wave, a stationary dislocation near the crack tip can either accelerate or delay attainment of a critical level of stress intensity, depending on the relative orientation of the crack, the dislocation, and the plane wave. However, if the incident wave also triggers dislocation motion, then the delaying effect is diminished and the acceleration is accentuated.

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