Composite materials have high in-plane mechanical properties, but are susceptible to out-of-plane impact damage. The use of non-destructive evaluation techniques, combined with mechanical testing, was investigated to characterize the progression of post-impact static and fatigue damage of composite laminates. Quasi-isotropic carbon/epoxy specimens were impacted at energy levels of 35 J and 50 J. The initial damage was characterized using ultrasonic C-scan and thermography. Residual strength testing revealed that the compressive static strength of the test specimens was reduced by over 50%. Digital image correlation was used to characterize the growth of damage and the local strain during compression-compression fatigue tests. Initially, no significant statistical trend could be measured when the fatigue data was plotted as a stress-life curve. When stress concentration factors were used to calculate and plot the local stress amplitude, a correlation with fatigue life was observed. The undamaged fatigue data was altered using damage factors which allowed for post-impact fatigue life predictions.
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:MWU.1993/4374 |
| Date | 19 January 2011 |
| Creators | Komus, Alastair |
| Contributors | Singh, Meera (Mechanical and Manufacturing Engineering), Jayaraman, Raghavan (Mechanical and Manufacturing Engineering) Polyzois, Dimos (Civil Engineering) |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | en_US |
| Detected Language | English |
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