Effect of fracture surface roughness on shear crack growth
- New Hampshire Univ., Durham, NH (United States). Dept. of Mechanical Engineering
- Ohio State Univ., Columbus, OH (United States). Dept. of Engineering Mechanics
A model of fracture surface interference for Mode I fatigue crack profiles was developed and evaluated. Force required to open the crack faces is estimated from point contact expressions for Mode I stress intensity factor. Force transfer across contacting asperities is estimated and used to calculate Mode II resistance stress intensity factor (applied factor is sum of effective and resistance factors). Electro-optic holographic interferometry was used to measure 3-D displacement field around a Mode I fatigue pre-crack in Al loaded in Mode II shear. Induced Mode I crack face displacements were greater than Mode II displacements. Plane stress shear lip caused displacement normal to surface as the crack faces are displaced. Algorithms are being developed to track the displacements associated with the original coordinate system in the camera. A 2-D boundary element method code for mixed mode I and II loading of a rough crack (sawtooth asperity model) has been completed. Addition of small-scale crack tip yielding and a wear model are completed and underway, respectively.
- Research Organization:
- New Hampshire Univ., Durham, NH (United States). Dept. of Mechanical Engineering; Ohio State Univ., Columbus, OH (United States). Dept. of Engineering Mechanics
- Sponsoring Organization:
- USDOE; USDOE, Washington, DC (United States)
- DOE Contract Number:
- FG02-90ER45433
- OSTI ID:
- 6659512
- Report Number(s):
- DOE/ER/45433-2; ON: DE93011047
- Country of Publication:
- United States
- Language:
- English
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