A phenomenological cohesive term is proposed and added to an existing
cohesive constitutive law (by Roy and Dodds) to model the crack tip high inertia region
proposed by Gao. The new term is attributed to fracture mechanisms that result in high
energy dissipation around the crack tip and is assumed to be a function of external
energy per volume input into the system. Finite element analysis is performed on
PMMA with constant velocity boundary conditions and mesh discretization based on the
work of Xu and Needleman. The cohesive model with the proposed dissipative term is
only applied in the high inertia zone i.e., to cohesive elements very close to the crack tip
and the traditional Roy and Dodds model is applied on cohesive elements in the rest of
the domain. It was observed that crack propagated in three phases with a speed of 0.35cR
before branching, which are in good agreement with experimental observations. Thus,
modeling of high inertia zone is one of the key aspects to understanding brittle fracture.
| Identifer | oai:union.ndltd.org:tamu.edu/oai:repository.tamu.edu:1969.1/5783 |
| Date | 17 September 2007 |
| Creators | Karedla-Ravi, Shankar |
| Contributors | Reddy, J. N. |
| Publisher | Texas A&M University |
| Source Sets | Texas A and M University |
| Language | en_US |
| Detected Language | English |
| Type | Book, Thesis, Electronic Dissertation, text |
| Format | 3545800 bytes, 6577220 bytes, 3517506 bytes, electronic, application/octet-stream, application/octet-stream, application/pdf, born digital |
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