Simcenter Amesim-Simcenter 3D Motion Coupled Algebraic Equations

Coupled algebraic equations

When coupling Simcenter 3D Motion and Simcenter Amesim a set of control forces from Simcenter Amesim is applied on the mechanism bodies resulting in Simcenter 3D Motion. In turn sensors feed position, velocity and acceleration data back to Simcenter Amesim. Usually, the Simcenter Amesim forces are the product of state equations. This means Simcenter 3D Motion must integrate a set of differential equations from Simcenter Amesim. Representing the Simcenter Amesim state equations by "g" and the state variable by χ then the coupled equations of Simcenter 3D Motion become

The Simcenter Amesim equations are written in a general format to allow the implicit equations to be generated and solved by Simcenter 3D Motion.

The link between the two packages is written in such a manner as to allow the user to take advantage of the strengths of both packages. The general flow of the interface is given in the figure below. The user builds the model in each package and then couples the two models in the Simcenter 3D Motion workbench. The simulation is performed from within Simcenter 3D Motion or, using the "loader" package, it can be solved from within Simcenter Amesim. In either case the Simcenter 3D Motion solver is used. While the Simcenter 3D Motion solver is running, both the Simcenter 3D Motion results file and the Simcenter Amesim results file are written out. This means at the end of the simulation the user has access to the full post-processing capabilities of both Simcenter Amesim and Simcenter 3D Motion.

Figure 2: Flow of the Motion Simcenter Amesim Coupled Solution Process