http://imechanica.org/taxonomy/term/1416 Comments for "crack tip functions" en http://imechanica.org/node/2079#comment-6104 <p> Hi nguyen, </p> <p> I am working on your matlab source. </p> <p> &nbsp;why you use crack angle (alpha) for calculating jacobian of drdx in branch.m. </p> <p> Later, you use gauss point angle (tetha) to calculate drdx in j-integ? </p> <p> Another problem,is not related to your matlab source, do you know how could I calculate dynamic J-Integ, because there are terms which are related to velocity of auxiliary displacement and strain. </p> <p> thanks for your time, </p> <p> Damoon </p> <br class="clear" /> Sun, 09 Dec 2007 11:04:57 -0500 damoonmoetamedi comment 6104 at http://imechanica.org http://imechanica.org/node/2079#comment-5943 <p> Hi Stephano, </p> <p> &nbsp;Sorry for very late reply however I did not notice your post. </p> <p> I agree that the third and fourth functions are different from the one of another authors. However I did not find big differences between them. </p> <p> &nbsp;Concerning the derivatives, I used bad names for the variables. Using the chain rule, we write, f(r,theta) </p> <p> dfdx =&nbsp; dfdx1 * dx1dx + dfdx2 * dx2dx </p> <p> dfdy =&nbsp; dfdx1 * dx1dy + dfdx2 * dx2dy </p> <p> &nbsp;What you see in my code, dfdr is in fact dfdx1 and calculated in advance by hand as&nbsp; </p> <p> dfdx1 = dfdr * drdx1 + dfdt * dtdx1&nbsp; </p> <p> I just posted the corrected code with renamed variables. </p> <p> Hope that it was a bit of help. </p> <p> &nbsp; </p> <p> Phu&nbsp; </p> <br class="clear" /> Sat, 24 Nov 2007 04:07:34 -0500 vinh phu nguyen comment 5943 at http://imechanica.org