From 3177893ec3de88a3ecc8d66bf913bb492c62d746 Mon Sep 17 00:00:00 2001
From: Oliver Sander <sander@igpm.rwth-aachen.de>
Date: Fri, 22 Aug 2014 09:37:42 +0000
Subject: [PATCH] Compute Cosserat strain given only the gradient of the
deformation, and the rotation
[[Imported from SVN: r9847]]
---
dune/gfe/cosseratstrain.hh | 32 ++++++++++++++++++++++++++++++++
1 file changed, 32 insertions(+)
diff --git a/dune/gfe/cosseratstrain.hh b/dune/gfe/cosseratstrain.hh
index cc72745d..f69141f1 100644
--- a/dune/gfe/cosseratstrain.hh
+++ b/dune/gfe/cosseratstrain.hh
@@ -54,6 +54,38 @@ namespace Dune {
}
+ /** \brief Compute strain from the deformation gradient and the microrotation
+ *
+ * \param R The microrotation
+ */
+ CosseratStrain(const FieldMatrix<T,dimworld,dim>& deformationGradient,
+ const FieldMatrix<T,dimworld,dimworld>& R)
+ {
+ /* Compute F, the deformation gradient.
+ In the continuum case (domain dimension == world dimension) this is
+ \f$ \hat{F} = \nabla m \f$
+ In the case of a shell it is
+ \f$ \hat{F} = (\nabla m | \overline{R}_3) \f$
+ */
+ FieldMatrix<T,dimworld,dimworld> F;
+ for (int i=0; i<dimworld; i++)
+ for (int j=0; j<dim; j++)
+ F[i][j] = deformationGradient[i][j];
+
+ for (int i=0; i<dimworld; i++)
+ for (int j=dim; j<dimworld; j++)
+ F[i][j] = R[i][j];
+
+ // U = R^T F
+ for (int i=0; i<dimworld; i++)
+ for (int j=0; j<dimworld; j++) {
+ data_[i][j] = 0;
+ for (int k=0; k<dimworld; k++)
+ data_[i][j] += R[k][i] * F[k][j];
+ }
+
+ }
+
T determinant() const
{
return data_.determinant();
--
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