Plane Stress Stable Crack Growth and J-Integral/HRR Field
Abstract
Moire interferometry with line densities of 1200 and 40 lines per mm was used to determine the two orthogonal displacements surrounding a stably extending crack in a 2024-T3 aluminum alloy, single edge cracked specimen. The test protocol consisted of using the fine moire grating prior to and up to the onset of crack extension and the coarse moire grating for the ensuing crack extension up to delta a = 6 mm. The displacement fields were used to compute the J-integrals for various contours during crack tip blunting and crack extension. As expected, the far-field J-integral value prior to stable crack growth coincided with the LEFM strain energy release rate, G, and validated the experimental Procedure. However, the J values obtained from the near tip contour increased slowly while the far field J values increased rapidly with increasing stable crack growth. The HRR displacement field was computed from the experimentally determined far field J. The HRR displacement field agreed with the measured displacement field prior to stable crack growth since J = G. However, the HRR horizontal displacement field progressively deviated from the measured values with crack extension. Elastic-plastic fracture mechanics, Stable crack growth, J-Integral, HRR Field-, J-0 Theory, Moire interferometry, Eperimental fracture mechanics
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 01, 1993
- Accession Number
- ADA275761
Entities
People
- Albert S. Kobayashi
- G. B. May
Organizations
- University of Washington