Accession Number:

ADA188385

Title:

On the Energy Release Rate for Dynamic Transient Anti-Plane Shear Crack Propagation in a General Linear Viscoelastic Body.

Descriptive Note:

Technical rept.,

Corporate Author:

TEXAS A AND M UNIV COLLEGE STATION MECHANICS AND MATERIALS CENTER

Personal Author(s):

• Herrmann, J. M.
• Walton, J. R.

Report Date:

1987-09-01

Pagination or Media Count:

44.0

Abstract:

The problem of a semi infinite model III crack that suddenly begins to propagate at a constant speed is considered for a general linear viscoelastic body. A simple closed form expression for the Laplace transform of the energy release rate ERR is derived under the assumption that a Barenbatt type failure zone exists at the crack tip. The first two terms of a short time asymptotic series for the ERR is constructed and the rate at which the ERR converges to steady-state is studied. It is shown that the rate of convergence to steady-state is dependent upon crack speed and material properties. Moreover, it is found that whether or not a failure zone is incorporated into the model significantly influences both quantitatively and qualitatively the short and long time behavior of the ERR. This difference is important to predictions of stable vs unstable crack speeds based upon a critical ERR fracture criterion.

Descriptors:

• *CRACK PROPAGATION
• *ENERGY TRANSFER
• SHEAR PROPERTIES
• VELOCITY
• CRACKS
• FAILURE
• LAPLACE TRANSFORMATION
• ASYMPTOTIC SERIES
• SHORT RANGE(TIME)
• RATES
• VISCOELASTICITY
• LONG RANGE(TIME)

Subject Categories:

• Mechanics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE