GNU Octave packages for pre- and postprocessing of general 3D flexible bodies for MBDyn

[Reinhard]

    Dear GNU Octave developers,

I have written four packages for GNU Octave, which can be used for pre- and post processing of general three dimensional flexible bodies for the multibody dynamics software MBDyn (https://www.mbdyn.org/). Especially modal element data can be generated easily and efficient, based on material properties, boundary conditions and geometrical data. It is also possible to perform pre- and post processing of elastohydrodynamic lubricated journal- and slider-plain bearings, including flexible body data generation for bearing journal- and shell-elasticity.

I would like to contribute those packages to Octave Forge as external ones.

Below you can find links to HTML function references, benchmarks and to the GitHub repositories.

HTML function references:
https://drive.google.com/drive/folders/1AGk3Lv1iDyUuoDZWHLG-3PU_8lruBmBX?usp=sharing

Benchmark problems which have been solved with MBDyn by using those packages:

- Nonlinear dynamics of a BMW I4 crankshaft from eOSSP (www.evolution-fea.com)

- Elastohydrodynamic diaphragm journal plain bearing from Norman Owen Freund 1995 (https://ro.uow.edu.au/theses/1568/)

- Elastohydrodynamic contact problem with flexible journal- and shell-surface

- Transient rotor dynamics problem

https://drive.google.com/drive/folders/1gzyK4o9cvQbBgDui_c072qHA7K-QmLtf?usp=sharing

Package repositories:

Structural finite element package for linear statics and dynamics:

https://github.com/octave-user/mboct-fem-pkg

With this package you can generate meshes, assign material properties, loads, boundary conditions and impose linear constraints, assemble finite element matrices and vectors, solve linear static and eigenvalue problems, compute deformations and stresses, build and export reduced order models, import and export meshes and results.

Interface between GNU Octave and MBDyn:

https://github.com/octave-user/mboct-mbdyn-pkg

With this package you can generate MBDyn input files for curved beam structures and modal elements. You can also load output files and post process results. Especially hydrodynamic plain bearing data, which is quite complex, can be handled easily.

Interface between GNU Octave and numerical solvers (PaStiX, MUMPS, Umfpack, ARPACK, METIS and LAPACK):

https://github.com/octave-user/mboct-numerical-pkg

This package provides interfaces to several sparse solvers, which can be used to solve large scale general symmetric linear systems of equations and generalized symmetric eigenvalue problems. Usually those solvers are more efficient regarding CPU time and memory consumption than Octave's builtin chol, lu and eigs.

General purpose utility package which is used by the other packages mainly for starting processes like MBDyn , Gmsh and Ghostscript.
https://github.com/octave-user/mboct-octave-pkg

With this package you can start external processes and distribute function executions to multiple Octave processes.

I hope, that you can host those packages at Octave Forge.

Best regards,
Reinhard