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To do list for Fall 2020:
- Find sufficient test materials (steel and CFRP)
- Buy degreasing solvents from Home Depot in Waterloo
- Machine test specimens
- Prepare test specimens
- Ask or email professors about using tensile test machines
- Record and plot results
- Make conclusions about true adhesive strength and effect of surface preparation on adhesive strength
Goals for Material Testing:
Validate adhesive strength, i.e. compare technical data sheet values with our manufactured values
Determining how much adhesive is required per surface area bonded
Determining the necessity of a degreasing solvent, i.e. a surface preparation technique
Determining the necessity of abrasion, i.e. a surface preparation technique
Research Phase of Material Testing
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Single Lap Shear Test: (D1002, ISO 4587)
Specimen Preparation:
Two rectangular sections that are 25 mm wide, 100 mm long and 1.6 mm thick
An overlap length of 25 mm.
Fixture is used to ensure correct overlap and accurate alignment of the adherend.
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Testing Procedures:
Prepare at 6 9 adhesive joint specimens following procedures from the product’s technical data sheet
3 adhesive joints should be prepared without any significant surface preparation methodstechnique
3 adhesive joints should be prepared using degreasing solvent
3 adhesive joints should be prepared using surface preparation methods mentioned belowdegreasing solvent and abrasion
Place onto tensile testing machine and load until failure
Record stress and calculate an average overlap shear strength
Review data to check any abnormalities in data, these may suggest poor specimen preparation
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https://www.homedepot.ca/product/armor-all-cleaner-and-engine-degreaser-wipes-30ct-/1001097005
https://www.homedepot.ca/product/goof-off-power-cleaner-degreaser-fg686-946ml/1000831786
https://www.homedepot.ca/product/hdx-citrus-degreaser/1000756208
https://www.homedepot.ca/product/zep-commercial-3-78-l-citrus-cleaner/1000137863
Note: More information on Learn more about surface preparation can be found here.
Material Selection:
Technical Data Sheet uses: Steel (grit blasted)
We will use any regular steel and it will not be grit blasted due to limited resources.
Steel can be found from scrap resources or from E3
Potential Improvements to Design if Results Show Insufficient Adhesive Strength:
Controlling bond line thickness by using physical limiters such as a jig, or introducing spacer beads into the adhesive mix