[tag] local_coordinate_system

A local coordinate system used for tensor transformations.

It offers a simple way for input of anisotropic tensors w.r.t. a coordinate system. The basis vectors form a transformation matrix \(R = (e_0, e_1, e_2)\). For a given anisotropic tensor \(A\) parameter with the corresponding [tag] use_local_coordinate_system the tensor is rotated according to the formula: \(A' = R\cdot A\cdot R^T\).

For computations in transverse isotropic material models, we can create a coordinate system with only one base, where the last base is explicitly given. The other bases are set as implicit and computed from the given base as follows:

  • For a 2D coordinate system, the unit vector orthogonal to the given base is used as the first base,
  • For a 3D coordinate system, the given base vector, unit_direction, is set as the third base, \({\vec e}_2\). An arbitrary unit vector orthogonal to \({\vec e}_2\) is selected as the second base \(e_1\), and the first base \({\vec e}_0\) is calculated as \({\vec e}_0 = {\vec e}_1 \times {\vec e}_2\).

Child parameters, attributes and cases

Additional info

From Applications/ApplicationsLib/ProjectData.cpp line 404

  • This is an optional parameter.
  • Expanded tag path: local_coordinate_system
  • Go to source code: → ogs/ogs/master

Used in the following test data files