Thesis
The effect of adhesive bondline thickness on joint strength
Washington State University
Master of Science (MS), Washington State University
08/2014
DOI:
https://doi.org/10.7273/000004299
Handle:
https://hdl.handle.net/2376/125225
Abstract
Bondline thickness is an important factor considered when designing a bond joint. This project considered a ductile adhesive and a brittle adhesive to compare their effect on joint strength. Aluminum and composite adherends were used to bond using these two adhesives. The performance of an adhesive depends on the properties of the adhesive, the adherends being bonded, surface preparation on the adherends, the bondline thickness and the uniformity of the load. Optimal thickness of both the adhesives was determined by varying the bondline thickness. The ductile adhesive was found to be more sensitive to bondline variation than the brittle adhesive. The failure mode was cohesive for bondline thickness in the range of 0.002 - 0.012 inch and the failure mode transitioned from cohesive to adhesive over thickness 0.025 inch. The joint profile was tailored to determine the effect of varying bondline thickness along the gage section on the joint strength. Two profiles, concave and convex, were considered to study the behavior of adhesives. A third tapered profile was designed to study the manufacturing defects like misalignment which occurs during layup of the adhesive. The difference in the strength of concave and convex profile was observed to follow an opposite trend for the ductile and brittle adhesive. The ductile adhesive was more sensitive to tailored joints and stronger in the concave geometry; and the brittle adhesive was stronger in convex geometry. The failure mode for the tailored geometries was found to be a mix of cohesive and adhesive failure. The degree of cohesive failure was more in the convex profile for the ductile adhesive and in the tapered profile for the brittle adhesive.
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Details
- Title
- The effect of adhesive bondline thickness on joint strength
- Creators
- Varun Gupta
- Contributors
- Lloyd V Smith (Advisor) - Washington State University, Mechanical and Materials Engineering, School of
- 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
- Identifiers
- 99900896400301842
- Language
- English
- Resource Type
- Thesis