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Open tasks

Thank you for your interest in contributing to this code base. The following task are open for your contributions.

Local functions

  • Implementing a unit normal field function1 and its derivatives w.r.t. its coefficients \( \boldsymbol{x}_i \)

    \[ \boldsymbol{n} = \frac{\boldsymbol{a}_1 \times \boldsymbol{a}_2}{||\boldsymbol{a}_1 \times \boldsymbol{a}_2||}, \quad \text{with } \boldsymbol{a}_{\alpha} = \sum_{i=1}^n N^i_{,\alpha}(\boldsymbol{\xi}) \boldsymbol{x}_i \]

    To implement this, see link.

  • Support second derivatives

  • Add \( \operatorname{div} \) and \( \operatorname{curl} \) wrapper

Control routines

  • Dynamics (Explicit/ implicit time stepping)

Control routines - addons

  • Extended systems
  • Nonlinear dependence of \(F_{ext}\) on \(\mathbf{D}\) and \(\lambda\) for path-following techniques, see control routines.

Finite element helper

  • Implement a default mass matrix

Finite elements

  • Nonlinear Reissner-Mindlin shell 2
  • Kirchhoff-Love shell
  • 3D-Beam
  • Standard beam and plate formulations
  • Add calculation of different stress measures (push-forward or pull-back of PK2 stresses or similar)

Further addons

Code style

For details on the code style, refer link.

  1. This is usually needed for a Kirchhoff-Love shell implementation, see 3. ↩

  2. Alexander Müller and Manfred Bischoff. A consistent finite element formulation of the geometrically non-linear reissner-mindlin shell model. Archives of Computational Methods in Engineering, pages 1–47, 2022. doi:10.1007/s11831-021-09702-7. ↩

  3. J. Kiendl, K.-U. Bletzinger, J. Linhard, and R. Wüchner. Isogeometric shell analysis with kirchhoff–love elements. Computer Methods in Applied Mechanics and Engineering, 198(49):3902–3914, 2009. doi:10.1016/j.cma.2009.08.013. ↩