The Viscoplastic Crack Growth Behavior of a Compact Tension Specimen Using the Bodner-Partom Flow Law.
Abstract
Creep crack growth in IN-100 was studied using a hybrid experimental-numerical procedure (HEN). This procedure couples displacement data generated during creep crack growth tests to a finite element model of the test specimen. A standard compact tension specimen geometry was used in all cases. The computer program used herein is a two-dimensional plane stress/plane strain code that uses constant strain triangular elements and has the ability to release fixed nodes to simulate crack growth. This procedure is facilitated by using a Gauss-Seidel iterative solution technique that allows appropriate terms in the stiffness matrix to be changed between timesteps to accommodate changing boundary conditions due to crack growth. A variable timestep algorithm maximizes the timestep size during the analysis while maintaining good accuracy. Constitutive equations proposed by Bodner and Partom were used to account for the nonlinear, viscoplastic material behavior exhibited by IN-100 at high temperatures. Crack growth estimates generated with the HEN procedure were within 20 percent of the actual crack growth in the test specimens after times ranging from 5-14 hours.
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 01, 1981
- Accession Number
- ADA111126
Entities
People
- James W. Smail
Organizations
- Air Force Institute of Technology