Comninou contact zones for a crack parallel to an interface
- Clemson Univ., SC (United States)
- Lehigh Univ., Bethlehem, PA (United States)
One of the interesting features in studying the state of stress in elastic solids near singular points, is the so called complex singularity that gives rise to an apparent local oscillatory behavior in the stress and displacement fields. The region in which this occurs is very small, much smaller than any plastic zone would be, and therefore the oscillations can be ignored in practical applications. Nevertheless, it is a matter of interesting theoretical investigation. The Comninou model of a small contact zone near the crack tip appears to correct for this anomaly within the framework of the linear theory. This model seems to make sense out of a {open_quotes}solution{close_quotes} that violates the boundary conditions. Erdogan and Joseph, showed (to themselves anyway) that the Comninou model actually has a physical basis. They considered a crack parallel to an interface where the order of the singularity is always real. With great care in solving the singular integral equations, it was shown that as the crack approaches the interface, a pinching effect is observed at the crack tip. This pinching effect proves that in the limit as the crack approaches the interface, the correct way to handle the problem is to consider crack surface contact. In this way, the issue of {open_quotes}oscillations{close_quotes} is never encountered for the interface crack problem. In the present study, the value of h/a that corresponds to crack closure (zero value of the stress intensity factor) will be determined for a given material pair for tensile loading. An asymptotic numerical method for the solution of singular integral equations making use of is used to obtain this result. Results for the crack opening displacement near the tip of the crack and the behavior of the stress intensity factor for cracks very close to the interface are presented. Among other interesting issues to be discussed, this solution shows that the semi-infinite crack parallel to an interface is closed.
- OSTI ID:
- 175304
- Report Number(s):
- CONF-950686-; TRN: 95:006111-0261
- Resource Relation:
- Conference: Joint applied mechanics and materials summer meeting, Los Angeles, CA (United States), 28-30 Jun 1995; Other Information: PBD: 1995; Related Information: Is Part Of AMD - MD `95: Summer conference; PB: 520 p.
- Country of Publication:
- United States
- Language:
- English
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