Oisin-M / WOBBLE

Package for modal analysis and rigid body simulations, extending the EPFL Akantu code

WOBBLE: Solid Dynamics Simulation Tool for Large Translation and Rotations

Extending EPFL's Akantu package, WOBBLE (Waves Of Beams and other Bodies due to Loadings and Excitations) offers efficient and accurate simulation capabilities by utilising modal analysis and rigid body mechanics

Authors

• Oisín Morrison ([e-mail])
• Leonhard Driever ([e-mail])

Purpose

WOBBLE is designed to deal with situations where large translations and rotations may be at play. This makes the package suitable for the simulation of satellites in space, which is important for applications such as ClearSpace.

Key Features

• Efficient Numerical Solvers
• Accurate Results
• Ability to Model Both Clamped and Non-Clamped Bodies

Codebase

The project is structured using the following directory structure:

.
├── wobble
└── examples
     ├── sample_data_files
     └── sample_notebooks

where

• wobble contains the code for the WOBBLE package
• sample_data_files contains the files (mesh files, eigenmode files, force files, mask files, geometry files, material files) for running the examples
• sample_notebooks contains a number of sample notebooks showing how to run WOBBLE to obtain results shown in our report

Within wobble, there exists 5 main files, containing 5 key classes for the WOBBLE package:

wobble
├── ma_fundamentals.py
├── pure.py
├── rb_fundamentals.py
├── rb_simple.py
└── rb_coupled.py

where

• ma_fundamentals.py contains the abstract class MAFundamentals, which implements the main methods used across all other classes
• pure.py contains the PureMA class, which implements the solver using pure modal analysis (no rigid body motion). This is suitable for modelling scenarios where bodies are clamped
• rb_fundamentals.py contains the abstract class RBFundamentals, which implements the main methods used across all the rigid body mechanics solvers
• rb_simple.py contains the SimpleRB class, which implements the SimpleRB algorithm discussed in the report (implements rigid body mechanics and modal analysis in a decoupled fashion)
• rb_coupled.py contains the CoupledRB class, which implements the SimpleRB algorithm discussed in the report (implements rigid body mechanics and modal analysis in a coupled fashion)

Usage

Examples of notebooks are provided in the sample_notebooks folder.

The authors recommend the following:

• Use PureMA if rigid body mechanics are not important for the application (e.g. clamped beam)
• Use SimpleRB if the body is not expected to be subject to a large amount of fictitious forces due to its rotation
• Use CoupledRB if the beam is expected to be subject to a large amount of fictitious forces due to its rotation

Requirements

WOBBLE was tested with Python 3.8.10 and uses the following packages:

akantu==4.0.1
numpy==1.20.3
matplotlib==3.4.3
scipy==1.8.0

Other

For further details, please see our report or contact the authors