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 <title>iMechanica - a question about ALE method - Comments</title>
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 <title>a question about ALE method</title>
 <link>http://www.imechanica.org/node/3052</link>
 <description>&lt;p&gt;
hi, I&amp;#39;m a student studying ALE method. In the book of &amp;quot;Nonlinear Finite Elements for Continua and Structures&amp;quot; written by Ted Belytschko el, conservation equations which discribed in the reference configuration and current configuration are given out (see chapter 7). But how about Balance Laws in initial configuration?
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&lt;p&gt;
In initial configuration, the basis vector is not a function of time and we usually the simply coordinate as the basis(cartesian coordinate or cylindrical coordinate etc.). So when&amp;nbsp;calculating the gradient of something, just give out its partial derivative(except cylindrical coordinate)(for example,&amp;nbsp;in both the Updated and Total Lagrangian FEA method). But in the reference configuration in ALE, the basis is the function of time and the coordinate also should be the curved coordinate(not regular as cylindrical coordinate ), so&amp;nbsp;the&amp;nbsp;gradient of tensor is not too simply to get a partial derivative and&amp;nbsp;the Christoffel symbol maybe included. But&amp;nbsp;in the&amp;nbsp;eqn of&amp;nbsp;moment conservation in Ted Belytschko&amp;#39;s book(7.12.9), only&amp;nbsp;partial derivative is mentioned.
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&lt;p&gt;
&lt;img src=&quot;http://imechanica.org/files/Eqn1.gif&quot; alt=&quot;moment conservation in Ted Belytschko&amp;#039;s book&quot; title=&quot;moment conservation in Ted Belytschko&amp;#039;s book&quot; width=&quot;196&quot; height=&quot;52&quot; /&gt;
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&lt;p&gt;
I don&amp;#39;t know how does this happen.&amp;nbsp;And another question is whether there&amp;nbsp;is&amp;nbsp;any book or article mentioning the ALE form of&amp;nbsp;conservation equations&amp;nbsp;in initial configuration? Is there any&amp;nbsp;kind friend who would&amp;nbsp;like to help me out? I&amp;#39;ll appreciate that. Sorry for my poor English.&amp;nbsp; :)
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&lt;br class=&quot;clear&quot; /&gt;</description>
 <comments>http://www.imechanica.org/node/3052#comments</comments>
 <category domain="http://www.imechanica.org/taxonomy/term/357">Computational Mechanics Forum</category>
 <category domain="http://www.imechanica.org/taxonomy/term/76">research</category>
 <category domain="http://www.imechanica.org/taxonomy/term/2214">ALE in initial configuration</category>
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 <pubDate>Mon, 14 Apr 2008 04:24:44 -0400</pubDate>
 <dc:creator>Yan Liu</dc:creator>
 <guid isPermaLink="false">3052 at http://www.imechanica.org</guid>
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