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You love Ansys! But have you ever wanted access to a strong Multi-Body Dynamics (MBD) capability from within Workbench? It would be great to simulate the motion and all of the related physics of your mechanical assemblies. You could understand the behavior of your assembly during concept development and you could generate the loads needed for your component-level FEA.

The first part of the solution is MBD for Ansys, an ACT application that works within the Ansys Workbench user environment. MBD for Ansys provides basic rigid body MBD capabilities (with a robust solver and high-performance contacts) as well as the ability to export the MBD model to RecurDyn, high-end standalone MBD software that is described below. MBD for Ansys has the following key capabilities:

1. Automated, Intelligent Load Transfer Function - Load transfer consists of these steps:

• The user runs the MBD simulation.
• A body is selected.
• Forces on the body are plotted and the user selects output times in the simulation that have loads of interest.
• A static structural system is created in the project schematic window for each load case, including connections.
• The body loads are mapped to regions on the body geometry.
• The loads cases are analyzed.

2. Fully-Functional MBD Software Embedded in Workbench - MBD for Ansys is tightly integrated into Workbench with capabilities for MBD model development, editing and analysis, and post-processing. All of the MBD for Ansys toolbars can fit in a single row of the Mechanical window. The MBD Entities toolbar contains menus for defining Bodies, Joints, Force, Contact, Expressions, data Splines, and output data Requests. The MBD Post toolbar contains menus for animation, plotting, and load transfer. A new Multi-Body Dynamics system block is defined in the Workbench window in the usual manner.

3. Export the MBD Model to the Standalone RecurDyn Software – The capabilities of an MBD Workbench application may not always be sufficient to model and simulate a given system. In such cases it is critically important to have the ability to export the system to a standalone high-end MBD software tool without losing the work that has already been done. MBD for Ansys has a single command that exports the MBD model (including geometry) for use by standalone RecurDyn/Professional. All geometry, joints, forces and contacts are retained. Once the model is in RecurDyn it is possible to add controllers, belts, chains, bearings, flexible media (paper/film), and nonlinear (large displacement) flexible bodies to the system. You can add track assemblies for construction equipment and military vehicles. It is possible to do system-level optimization, including model variability.

4. High Performance Contact Modeling - MBD for Ansys uses RecurDyn technology to solve contacts efficiently. For example, the modeling of a gear pair, having many surfaces on each gear that can contact each other, was done 100x faster with MBD for Ansys as compared to other Workbench options. In this case the gear pair rotates at a high speed for 0.7 seconds and is simulated in 3 seconds. The magnitude of the speedup depends on the complexity of the contact problem. With MBD for Ansys you will experience the fastest simulation of models with contact.

5. Advanced MBD Post Processing Tool – MBD for Ansys can plot output forces and perform the load transfer process within the Mechanical window. MBD for Ansys can also launch an external post processing tool with the following functions:

• Animation with cameras and advanced plotting.
• Ability to define combined views of animations / plots.
• Animations can be saved to an avi file.
• Curve data can be mathematically processed and filtered.
• Plot data can be exported to a text file that can be imported by Excel.

The second part of the solution is RecurDyn, which provides high-end multi-body dynamics (MBD) simulation capabilities for assemblies in motion. RecurDyn has capabilities to simulate machinery with chain or belt systems; the combination of many rigid and flexible components; tracked vehicles; systems with flexible media; mechatronics systems; and assemblies that interact with dry particles and particle-based fluids. RecurDyn can import Ansys modal outputs and mesh data in order to solve complex mechanisms. Load and displacement outputs from RecurDyn and MBD for Ansys can be used to define boundary conditions for advanced structural models in Ansys.

Additional Resources:

MBD for Ansys information
RecurDyn information
Global Network