I don't know MBDyn, but it sounds like it would be in the same ballpark as Modelica. Saso has a keen interest in something like this, but so far no real development has taken place; see Modelica.josegegas wrote: ↑Sun Sep 08, 2019 5:21 amI've been using MBDyn to do simulations of engines and other mechanisms. It is a free and open source multi body dynamics software. It is very powerful but it lacks pre and post processing graphic interface. I've been using FreeCAD as pre and post processing tool for MBDyn and all works very well. Both programs can be integrated nicely through python scripts. I think they could also be integrated in a new workbench.
Sounds great that you had the same idea! Would you mind sharing some details? My approach has been to create customized objects in FreeCAD that contain the properties of each object required by MBDyn. Thus, I create a "Gravity" object in FreeCAD that has the gravitational acceleration and the direction vector. There is also a "Rigid Body" object that has the mass, center of mass, inertia tensor, etc. A "Node" object that has the initial conditions, etc... Then my Python script reads the objects and writes the txt file (.mbd) to be read by MBDyn. I then run the simulation, and read the output files to animate the objects in FreeCAD. What is your approach?
Why would you need assembly 4? I mean, MBDyn already takes care of the mechanism assembly. It will yield an error if the assembly was not consistent. My approach to animate the simulation results is just to use a timer (imported from Qt) to update each part's position and orientation. This is very straightforward since MBDyn writes the simulation results in a simple text file, from where all I do is read the values and move the 3D objects accordingly. MBDyn gives me XYZ positions and Euler angles, exactly what FreeCAD loves haha
I thought exactly the same. There is no need for constraint solver because MBDyn already does this. My idea is to use FreeCAD only as pre and post processor. MBDyn is already a very powerful tool. If we could use FreeCAD to make MBDyn more user friendly, by avoiding the complicated input files, this would be awesome!