Tenth
Lab Task: Life-tested samples; bond strength tests
Marine
Adhesives
Nov.
6, 2001
Dr.
Sichel
Testing
bond strength in MMA's strength of materials testing lab
Go
to the floating dock and harvest the PSI-326 samples in the
minnow cage. There are two minnow cages tied to the floating
dock. One cage contains a couple of life-test samples of PSI-326
epoxy (heavy aluminum and oak wood fixtures). It was deployed
on Oct. 18, 2001. (The other cage contains several adhesives,
each one is in a mesh bag with a Tyvek label. It was deployed
on Sept. 25, 2001.)
Prof.
Robideau is in charge of the strength of materials lab and
he will show us how to perform the tests. Cadet 2/C Pike is
enrolled in Prof. Robideau's class and he will assist and
provide information to our technicians.
Before
loading a sample into the testing machine, blot it gently
with paper towels to dry it. Keep a careful record of each
sample tested and the force (in pounds) at which it failed.
Also note the theoretical area of the bond and your best estimate
of the % coverage, based on your examination of the adherends
after the bond failed. Was it a failure of adhesion or a failure
of cohesion? We will be able to test the heavy aluminum fixture.
Depending on what kinds of adapters there are in the lab,
we might be able to do a compression test on the oak wood
fixture.
| sample |
force@failure |
area |
%
coverage |
failure
mode |
psi,
actual |
| |
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|
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Complete
your calculations of psi theoretical and psi actual.
|
