Definition and Modeling of Critical Flaws in Graphite Fiber Reinforced Epoxy Resin Matrix Composite Materials.
Abstract
Typical flaws are identified and static analyses developed or presented to predict their growth. A 'wearout' fatigue concept is incorporated into the static/fatigue model and the concept of an instability boundary established for every flaw size and location. An experimental program is outlined to support the analysis and to measure the specific adhesive surface fracture energy quantitatively. Acoustic monitoring of the specimens to detect damage growth and a corresponding vibration analysis are carried out as a potential NDT and for correlation studies. Ultrasonic 'C' scans are used to ensure quality control and to determine approximate damage growth rates. The analytical and experimental results are incorporated into an NDE technique to quantitatively determine a measure of the residual lifetime and strength of the structural component. A comparison of these with a quantified criterion for damage tolerance would establish flaw criticality through the need, or lack of it, for mandatory repair.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 1978
- Accession Number
- ADA061053
Entities
People
- R. B. Pipes
- R. L. Ramkumar
- S. V. Kulkarni