FEA ANALYSIS

General-purpose multi-physics design and analysis software for a wide range of applications

INTEROPERABILITY

Built-in circuit modelling and interfaces to leading CAD packages

SERVICE

Technical support, training and consultancy services available for software usage and applications

OPTIMIZER

Automatically selects and manages multiple goal-seeking algorithms

Python in Opera FEA Arturas Venskus, Danail Vassilev, Alex Coleman

30th Anniversary Event

Cobham Technical Services EUGM 2014

Python in Opera FEA

Contents

– What is the Python?

• Introduction

• Code snippets

– Python in Opera FEA

• New PYTHON command

• Opera FEA python interface

• COMI & Python

• Client server

• Matplotlib

– 2d rotational motion example

• Problem description

• Steady State Detection

• Wavelet Transform

• Wavelet analysis of simulation data

• Live demo

– Conclusions

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Cobham Technical Services EUGM 2014

Python in Opera FEA

Introduction

• From www.python.org: Python is a programming language that lets you work quickly and integrate systems more effectively; Python is powerful... and fast; plays well with others; runs everywhere; is friendly & easy to learn; is Open

• Python supports multiple programming paradigms, including object-oriented and procedural programming

• Widely used in mixed programming environment as scripting and gluing tool

• Comes with batteries included – Python Standard Library

• Becomes de facto standard for scientific and engineering computations

• Very large ecosystem of accompanying 3rd party high quality open source and commercial python libraries for scientist and engineers

• CAD/CAM/FEA/PLM software exposes their interfaces to the python

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Cobham Technical Services EUGM 2014

Python in Opera FEA

Code snippets

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Python class

Python strings

Python string methods:

• str.capitalize() • str.count • str.find • str.format • str.lower() • str.upper() • …

Python lists (vectors)

File handling

Python dictionaries

Cobham Technical Services EUGM 2014

Python in Opera FEA

New PYTHON command

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PYTHON command=‘python statement’ PYTHON file=‘python_script_file.py’

Cobham Technical Services EUGM 2014

Python in Opera FEA

Python module interface

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PYTHON command=‘import OPERAFEA’ PYTHON command=‘ofea = operafea.interface()’ PYTHON command=‘print dir(ofea)’ … 'addConstantUsrVar', 'addEquationUsrVar', 'addModelDimUsrVar', 'addParameterUsrVar', 'command', 'getUsrVar', 'getUsrVarDescr', 'getUsrVarExpr', 'getUsrVarStr', 'output', 'removeUsrVar‘ …

Embedded Opera FEA python module Usage example

rectangle.py

Cobham Technical Services EUGM 2014

Python in Opera FEA

COMI & Python

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COMI script Python scripting

COMI can call Python, Python can call COMI

Cobham Technical Services EUGM 2014

Python in Opera FEA

Client-server

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Python and interprocess communication (IPC)

Opera FEA Mutliphysics Suite Framework • numpy/scipy Arrays, Matrices, Complex numbers

• matplotlib Advanced

3D plot

• OpenTURNS, EDF

Sensitivity analysis

• H5PY HDF file handling

• Dacota (Sandia Lab)

Optimisation

• OpenFOAM CFD

• Code_Aster, EDF

Structural and Thermal FEA

• EnSight

• SALOME PRE/POST

Cobham Technical Services EUGM 2014

Python in Opera FEA

Matplotlib

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• Opera B field

• Maplotlib 3D B field

•Maplotlib samples

Cobham Technical Services EUGM 2014

Python in Opera FEA

2D rotation motion example

– RM Analysis

– Analysis purpose is detection of steady state by using Python wavelet library

Python script (IPC), Wavelet lib

Solver

Control COMI

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Cobham Technical Services EUGM 2014

Python in Opera FEA

Our analysis requires ability to:

• remove the noise if present

• detect statistical changes (e.g. mean)

• detect periodic event and estimate its parameters (frequency or period)

Need most suitable representation of the simulation data in order to extract useful features.

Steady State Detection

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Cobham Technical Services EUGM 2014

Python in Opera FEA

Wavelet Transform

• Express signal/data in terms of basis functions with short duration – wavelets.

• Wavelet transform provides both time and scale(frequency) information. Useful for analyzing non-stationary signals, denoising, detects abrupt changes, compresses data.

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Cobham Technical Services EUGM 2014

Python in Opera FEA

Wavelet power density of two sinusoids with periods 120s and 36s. The algorithm captures accurately the periods and the localisation of the modes.

Wavelet analysis of simulation data

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Cobham Technical Services EUGM 2014

Python in Opera FEA

Conclusions

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• Object oriented programming in Opera

• Advanced string handling in Opera scripts

• Arrays, vectors and all python data structures in Opera scripts

• Complex numbers in Opera scripts

• Fast prototyping of ideas

• Easy connection to the 3rd party libraries and software

Cobham Technical Services EUGM 2014

Python in Opera FEA 14