From: Johannes Friedlein Date: Tue, 28 Dec 2021 18:28:49 +0000 (+0100) Subject: docu of fourth order unit tensor: typo in index notation X-Git-Tag: v9.4.0-rc1~689^2 X-Git-Url: https://gitweb.dealii.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=5943af68766df7ee039a7bb9b36ce17e89a8eb5e;p=dealii.git docu of fourth order unit tensor: typo in index notation corrected minor typo in documentation of fourth order unit tensor (or "fourth order identity tensor") \mathcal{I}_{ijkl}, compare for instance Wriggers "Nonlinear Finite Element Methods" p.79 eq. (3.270) or [Notes on Continuum Mechanics - Tensors](http://mmc.rmee.upc.edu/documents/Tensor_Analysis/tensors.pdf) eq. (1.175); appears to be a copy-paste error from previous line 101 --- diff --git a/include/deal.II/base/symmetric_tensor.h b/include/deal.II/base/symmetric_tensor.h index 5e539e7370..ceb538ef89 100644 --- a/include/deal.II/base/symmetric_tensor.h +++ b/include/deal.II/base/symmetric_tensor.h @@ -99,7 +99,7 @@ DEAL_II_CONSTEXPR inline DEAL_II_ALWAYS_INLINE SymmetricTensor<4, dim, Number> * In index notation, we can write the general form * \f[ * \mathcal{I}_{ijkl} = \frac 12 \left( \delta_{ik} \delta_{jl} + - * \delta_{il} \delta_{jl} \right). + * \delta_{il} \delta_{jk} \right). * \f] * To see why this factor of $1 / 2$ is necessary, consider computing * $\mathbf A= \mathbb I : \mathbf B$.