1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Homework Help: Reverse Engineering Derivations - How?

  1. Mar 29, 2012 #1
    1. The problem statement, all variables and given/known data
    I have to reverse engineer a derivation in a paper and have no idea where to even start. The amount of terms are overwhelming and I can't imagine how the author even began.

    2. Relevant equations
    The following equations are known:



    Substituting them into the following equation gives an expression where [itex]r[/itex] needs to be isolated.


    The author makes many substitutions and results in the following simplified equation.


    The substitutions are as follows:




    What I'm trying to do is figure out how he arrived at these coefficients [a], , [c], V, etc.

    3. The attempt at a solution
    I've substituted (1)--(5) into (6) but don't know where to go from here. The equation is huge and has many terms. I'm not sure how/where to begin.

    Any help will be much appreciated. Thanks.
  2. jcsd
  3. Mar 29, 2012 #2
    Out of interest, for what course is this?
  4. Mar 29, 2012 #3
    This is for a graduate level Fracture Mechanics course.

    The title of the paper is: The effect of T -stress on crack-tip plastic zones under mixed-mode
    loading conditions.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook