MSC.Dynamic Designer Motion Professional 2005

Studying Physics-Based Motion Behavior.

MSC.DYNAMIC DESIGNER 2005 is a general-purpose motion simulation package originally developed by Mechanical Dynamics, now part of MSC.Software. Basically, it's a tool for studying the physics-based motion behavior of a CAD design without leaving the CAD environment, in this case Autodesk Inventor. MSC.Dynamic Designer 2005 is certified for use with Inventor 10, as well as Solid Edge.

MSC.Dynamic Designer Motion Professional 2005

MSC.Dynamic Designer comes in three product levels for different needs:

• 1. Simply Motion, for driving assemblies.
• 2. Motion, for studying collision and plotting and viewing basic results such as velocity and acceleration.
• 3. Motion Professional, for studying more advanced types of movement, applying forces and importing results into other FEA applications for stress analysis.

Any one of these levels is suitable for use by mechanical designers as opposed to specialized structural engineers, although a basic understanding of the physical principles contained within MSC.Dynamic Designer is definitely beneficial and desirable. For this review, we'll look at Motion Professional.

Ideally, Dynamic Designer is used in conjunction with the stress analysis tools found in Autodesk Inventor Professional or other FEA tools. In this scenario, you use Dynamic Designer to analyze motion and generate loads as input before transferring the data to Inventor or any other tool for FEA (finite-element analysis).

Some of the general capabilities of Dynamic Designer include:

• 1. Visualizing complex linkage movement
• 2. Visualizing collisions and interferences between parts
• 3. Designing and developing cam profiles
• 4. Determining power requirements and consumption
• 5. Evaluating effects of friction on systems
• 6. Deriving, animating, and plotting engineering results.

You can use Dynamic Designer to analyze general machinery designs such as material handling, robotics, cams and latches, packaging equipment, hand tools and consumer products.

To start MSC.Dynamic Designer, select it from Inventor's Tools menu. Next, you must activate the IntelliMotion browser from Inventor's Assembly browser and change the tree display from Model to Motion. A graphical, hierarchical view of the motion model is then displayed.

Figure 1. MSC.Dynamic Designer lets you get a better understanding of how a design works by displaying force vector arrows in conjunction with a mechanism s movement.

Before you can simulate a mechanical system, you must create a mechanism model for an assembly. In the IntelliMotion browser, select the components from the Inventor assembly that you want to use in the motion model by dragging and dropping them. Once you've selected all the mechanism's components, apply constraints to joints in the mechanism and define motion drivers to drive the joints. Optionally, you can define gravity, springs, dampers and other loads acting on the mechanism.

Next, define how a mechanism's parts will move by setting up constraints. Forces and materials must also be applied. Finally, designate the component parts of the assembly that will be included in the motion simulation and represent a rigid body whose motion will be simulated. You can designate a part as a moving part (that has six degrees of freedom) or a nonmoving, grounded part (that has no degrees of freedom). Joints are added between parts to constrain how the parts move relative to each other. You can also use a fixed joint to rigidly connect parts.

With everything defined, you're ready to run a motion simulation. Display the Show Simulation panel, modify any simulation settings by clicking the Options button, and select the Simulate button to run the simulation.

After simulating an assembly, you have several options for reviewing the results, including:

• 1. Animation
• 2. Interference check
• 3. Display result symbols
• 4. Plot numerical data
• 5. Export results to Excel spreadsheet, text file, or FEA application.

Motion analysis and simulation are powerful tools if you deal with mechanisms that require a high level of motion understanding. MSC.Dynamic Designer is well-suited for such tasks, especially when paired with Autodesk Inventor.

Jeffrey Rowe is an independent mechanical design and technical communications consultant. With offices in Colorado and Michigan, he can be reached at 719.539.8549 or jrowe@cairowest.com.