Revision of Characterising fracture toughness in epoxy using mechanical fatigue. Help! from Fri, 2009-07-03 14:50

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Hi all,

I have taken up this research project/attachment on
"characterising the fracture toughness of epoxy using mechanical
fatigue", and encountered lot's of problems while researching. I'm just
a student, not even in university, but rather still schooling (grade
10), so am completely new to this field, which explains my problem in
understanding all the lit reviews, lecture slides i found online.
Luckily, i found out this site, and would hope that someone can guide
me in the right direction!

So far, i have read some
articles/files on fracture mechanics, but sadly, its kind of hard for
me to understand. What i understand about my project is that i have to
propagate a crack using mechanical fatigue (cyclic loading) on an epoxy
specimen (SENB), so as to find out the fracture toughness of the
material. 

I would like to ask, how do i go about designing the
experiment? For instance, how do i prepare the specimen, fatigue the
crack, how will the results be like and how do i analyse the results to
find out what i want?

I am supposed to subject the epoxy
specimen under cyclic loading, until the crack propagates. My mentor
told me that there will be 2 approaches, the displacement control
approach and the force control approacb for the cyclic loading. Which
is better and why? Also, what kind of sensors and detectors do i use to
measure the crack growth?

Another issue would be Kc and Gc. I find it hard to understand the relationship between these 2, can anyone explain it to me?

I
know my post may seem very easy and general to you guys here, but for
me, its new! Thus, i would appreciate if anyone can guide me along!
Will definitely learn and research more!

 Thanks!Foot in mouth