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<DIV><FONT face=Arial>Hi,</FONT></DIV>
<DIV><FONT face=Arial>I am used to use the Ofelib(one fem lib) to resolve the
fem problem, but when I find that itk also has the fem lib I intend to
use it in my app. I create a .fem file and use the itk::fem::solver by
reading the .fem file. However, two problems make me very puzzled.</FONT><FONT
face=Arial></FONT></DIV>
<DIV><FONT face=Arial></FONT> </DIV>
<DIV><FONT face=Arial>1.if the size of the mesh is large, e.g. the number of the
nodes > 1000, the solver will take a very very long time(1-2 hours) to finish
the computation. I once use other fem libs such as Ofeli which only take 15
minutes.</FONT></DIV>
<DIV><FONT face=Arial></FONT> </DIV>
<DIV><FONT face=Arial>2.I fix some Dof when applying BC , However, the
solution is not same with the values I set on these DOF.</FONT></DIV>
<DIV><FONT face=Arial></FONT> </DIV>
<DIV><FONT face=Arial>I look at the source code of itk::fem and I find it use
the iterative least square to solve the linear system. I do not know
if this is the reason causing the very long time computation.
Becaus the Ofelib use the CG to solve the linear system and
only need very little time.</FONT></DIV>
<DIV><FONT face=Arial></FONT> </DIV>
<DIV><FONT face=Arial>I only need solve the static linear elastic problem, use
the tetrahedron as the element of the mesh. </FONT></DIV>
<DIV><FONT face=Arial></FONT> </DIV>
<DIV><FONT face=Arial><MaterialLinearElasticity><BR> 0 %Global
material number<BR> E: 3000 % E<BR> A: 0 % A<BR> I: 0
% I<BR> nu: 0.45 % nu<BR> h: 1<BR> RhoC:
1<BR> </FONT></DIV>
<DIV><FONT face=Arial><Element3DC0LinearTetrahedronStrain></FONT></DIV>
<DIV><FONT face=Arial></FONT> </DIV>
<DIV><FONT face=Arial></FONT> </DIV>
<DIV><FONT face=Arial>thnk you in advance!</FONT></DIV>
<DIV><FONT face=Arial></FONT> </DIV>
<DIV><FONT size=2><FONT face=Arial size=3>Yixun Liu</FONT></DIV>
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