Reminders

• Part 2 due
• Tuesday
  • ROM Hw due (canvas or paper)
  • ppt presentations (uploaded to canvas)
• Thursday
  • Project Report + Teammate eval due
• A week from monday
  • 3/13 - Final exam at 8AM
• 3/15 at noon
  • Lab clean up
• Mario Kart, Friday 3/3
  • 2420 Lisa Lane at 8ish
• Final Review + Course Eval. for +5 points due THURSDAY 3/9
• We show our ppt on thursday but ppt is still due on tuesday
  • Powerpoint is 20min MAX
  • Aim for 10-15 minutes
• What people present could be on the final in the sense that general lessons learned could be on the final
  • ex. when it comes to female tooling blah blah blah is more difficult

Notes

• Testing of composites:

  1. Destructive Testing: Destroys the item

     1. Mechanical testing
        1. Tensile
        2. Flexural
        3. Short Beam shear

  2. Non-Destructive: allows you to find delams and what not without destroying the part

     1. Ultrasound
        1. Through Transmission
           1. Need to be able to access both sides of your part
           2. Need a coupling mechanism, eg water, gel, etc
        2. Pulse Echo
           1. Only need access to one side of your part
        3. You will get signals back, and when you see a distinct spike you know the
     2. Visual
     3. Tap testing
        1. Use a tap hammer to tap along the surface of the composite’s surface to test for delaminations
     4. X-Ray
        1. Only works for mat’ls that show up on xray
        2. Some mat’ls are damaged by x-ray
     5. Visual Inspection
        1. Literally looking at the part
           1. If you see a bump there’s a delamination
        2. Microscope
     6. Infrared Thermography
        1. AKA Thermography
        2. Uses IR to heat up a source, there will be a temperature difference where there is a defect: delam, crack, moisture
     7. Dye Penetrant
        1. Put a dye on the surface, then wipe off the dye, wherever the dye hasn’t been wiped away, there is a crack because it seeps in
     8. Eddy Current
        1. Induce a current through the part
        2. Similar to ultrasound
     9. “Comparison of Techniques” (Slide)
        1. This slide is more for your reference in the future to see what techniques are best to find whatever defect you are looking for
     10. There are NDT (Non Destructive Technique) guides

     <aside> 💡 on the exam 3 example of non-destructive testing will be asked for

     </aside>

  • All of the testing methods have standards associated with them
    • An important one is the ASTM
      • You can use the Illiad (ill-ee-ad) through the school to get the ASTM standard you want, sent to you for free, electronically

• ASTM

  • Tells you how to setup your testing method
  • Tells you the procedure for the test
  • Tells you how to calculate the outputs

• Types of Repair

  • fig 1 - Patch Repair
  • Patch Repair
    • Adding material over where the issue is
    • When to use
      • Field Work
      • Temporary
      • Non-structural
    • Good because
      • Little equipment needed
      • Little expertise
      • Fast
  • Scarf Repair
    • fig 2
    • Remove damaged area
    • Replace removed area with a different material, ensuring that the area is just as strong, and not stronger, than before
  • Step Repair
    • Fig 3
    • Remove damage layer by layer
  • Scarf + Step Repair
    • Take equipment, sanding to remove material
    • Not done in the field
    • Take resources
    • Takes skilled labor