Thesis
1-dimensional microvascular network in carbon compostie for enhanced radiographic imaging
Washington State University
Master of Science (MS), Washington State University
2014
Handle:
https://hdl.handle.net/2376/101477
Abstract
Damage in composite materials can be present in many modes. Locating the damage is critical for safe operation of composite structures. Different non-destructive tests have been developed by industry to detect internal damage. Radiographic imaging can provide good flaw resolution, as long as the contrast between the defect and surrounding material is high. To increase the contrast, radiographic penetrants can be included. This work embedded a microvascular network of hollow glass fibers (HGF) to internalize the radiographic penetrant. These fibers were filled with penetrant, and cured between plies of composite prepreg. After curing, the composite was loaded, inducing damage that ruptured the HGF. This allowed for the release of the penetrant into the damaged areas, enhancing the radiographic imaging without soaking the composite in penetrant. Selection of HGF used to produce a microvascular network is designed on two main properties. The HGF needs to be strong enough to withstand stress during cure. The HGF needs a large hollow interior to ensure maximum penetrant inclusion. Validation of detecting matrix cracks was done by performing a shear lag analysis. Comparing the predicted crack density to measured crack density showed a difference of 12.8% and 5.48% for laminate thickness of 6 and 12 plies respectively. Delamination verification compared the detected delaminated area to delaminations measured using Digital image correlation, which had an average difference of 1.41%. Evaluation of the effect of the HGF on the mechanical properties was performed. The effect was highly dependent on the composite layup surrounding the HGF. For most layups, the properties were reduced, with an average loss in strength of 8.73%. Ex, modulus of elasticity in the loading direction, had the most variation in the effect, having 3 of 8 layup having an increase in Ex.
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Details
- Title
- 1-dimensional microvascular network in carbon compostie for enhanced radiographic imaging
- Creators
- Peter S. Damstedt
- Contributors
- Lloyd V. Smith (Degree Supervisor)
- Awarding Institution
- Washington State University
- Academic Unit
- Mechanical and Materials Engineering, School of
- Theses and Dissertations
- Master of Science (MS), Washington State University
- Publisher
- Washington State University; [Pullman, Washington] :
- Identifiers
- 99900525071101842
- Language
- English
- Resource Type
- Thesis