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- one of the main takeaways of this document is that debonding of the core and face laminate can cause failure of a honeycomb sandwich panel.
- This debonding can occur when there is too much pressure (relative to ambient pressure) inside the cells of the honeycomb.
- essentially, this excess pressure pushes up on the laminate face, causing it to disbond from the core.
- By symmetry, we can assume that there is no net force on the other honeycomb cells due to excess pressure. Therefore, the main failure mode of overpressurization is disbond between the face and the core.
Document on honeycomb bond failures: http://www.tc.faa.gov/its/worldpac/techrpt/artn0657.pdf
Personal notes and journal for other honeycomb research and happenings is here.
Honeycomb sandwich panel coupons were tested in tension. For details, see the Google Doc linked above. The team will also test the coupons in a vacuum chamber. The team used unperforated honeycomb in this first set of coupons just to build familiarity with working with honeycomb. However, if the team wishes to use unperforated honeycomb on high altitude flights, the team must make sure that the pressure difference between the inside of the honeycomb cells (sea level) and at apogee will not damage the honeycomb or cause failure of the sandwich panel.