Depuis la version 2026, Flux 3D et Flux PEEC ne sont plus disponibles.

Veuillez utiliser SimLab pour créer un nouveau projet 3D ou pour importer un projet Flux 3D existant.

Veuillez utiliser SimLab pour créer un nouveau projet PEEC (pas possible d'importer un projet Flux PEEC existant).

/!\ La documentation est en cours de mise à jour – des références au 3D peuvent subsister.

Six Degrees of Freedom

Introduction

A new type of Mechanical set has been implemented to able to take into account the Six degrees of freedom of a motion.

It is now possible to apply a rotating and/or translating movements to the moving mechanical set at each resolution step.

Three workflows are possible:

Drive a "free" mechanical set with multiphysics parameters in order to co-simulate with Activate
Drive a "free" mechanical set with multiphysics parameters by using Flux multiphysics context
Drive a "free" mechanical set directly in Flux with parameters controlled by a scenario

What's 6 degrees of freedom?

There are 6 possible motions, 3 translations and 3 rotations with independent directions:

In space, using an orthonormal coordinate system (O,x,y,z), the 6 degrees of freedom are defined as follows:


Degree of freedom	3D	2D
Translation along the X axis
Translation along the Y axis
Translation along the Z axis
Rotation around the X axis
Rotation around the Y axis
Rotation around the Z axis

Create a 6 degrees of freedom mechanical set

Open the dialog box of the creation of a mechanical set:
Click on Physics > Mechanical Set > New
Choose the name of the Mechanical set
Choose Six degrees of freedom type
On Defintion tab, choose the Coordinate system
On Kinematics tab, choose the Multiphysic for the Type of kinematics

Remarque : There is no choice, the Multiphysic type is the only choice (no coupled load or imposed position/speed for this type of mechanical set)

Validate by clicking on OK

→ the mechanical set is created and displayed on the data tree

→ I/O parameters are automatically created ( six for a 3D project, and three for a 2D project)


Data Tree in a 2D project	Data Tree in a 3D project

→ By default the parameters associated to the "6 degrees of freedom" Mechanical Set are multiphysic parameters. These parameters can be directly used:

in a coupling with an other software like Activate.
in the multiphysic context of Flux

→ If you want to use a 6 degrees of freedom mechanical set directly in Flux, you should edit the parameter and change type from Parameter for multiphysical application to Parameter controlled by a scenario

Workflow: multiphysics parameters used by Activate

Create the mechanical set with the type "6 degrees of freedom"
Assign the mechanical set to the wished regions
Generate a Flux-Activate component, by clicking on Solving > Generate component for Activate coupling
Go to Activate to pilot the co-simulation

Workflow: multiphysics parameter used by Flux multiphysics context

Create the mechanical set with the type "6 degrees of freedom"
Assign the mechanical set to the wished regions
Open a Flux multiphysics context by right clicking on a scenario (previously created) and choosing Multi physic solving session (existing scenario)
Go to the next step by clicking on Multiphysics solving > Activate the next step
Update the value of multiphysics parameters by clicking on Parameter/Quantity > I/O Parameter > Update current value of a multiphysics I/O parameter
Solve the step by clicking on Multiphysics solving > Solve the current step
Replay 4 - 5 - 6 if you want other steps

Remarque : these steps can be done by python with a loop to solve automatically the list of steps which you want
Close the multiphysics context
Post-process

Workflow: parameter controlled by a scenario

Create the mechanical set with the type "6 degrees of freedom"
Assign the mechanical set to the wished regions
Edit predefined parameters
Change the type from Parameter for multiphysical application to Parameter controlled by a scenario
Create a scenario and use these parameters to pilot the scenario
Solve
Post-process