Mechanism Design and Mechanism Dynamics > Mechanism Dynamics > Using Mechanism Dynamics > To Create a Model for Mechanism Dynamics
To Create a Model for Mechanism Dynamics
Creating a model for Mechanism Dynamics analyses includes these tasks:
Defining the bodies in your model—A body is a group of parts that are rigidly controlled with no degrees of freedom within the group. If two parts have no degrees of freedom between them due to the placement constraints that were defined during the assembly process, they are part of the same body. You can only place predefined connection sets between two distinct bodies. If a mechanism is not moving the way you expect, or if you are not able to create connections because two parts are in the same body, you may need to redefine the bodies in your mechanism.
Assembling the model—When you open an existing model in Mechanism Design, you can add other types of joints and modeling entities. The connection sets define how the components move with respect to each other.
Assigning mass properties—You must assign mass properties to your mechanism before you run a dynamic or static analysis. You must also assign mass properties before you run a force balance analysis if you want to include gravity in the analysis. If you have not assigned the mass properties in your assembly, you can do it in Mechanism Design.
Specifying connection parameters—After you add connections, use the Motion Axis dialog box to define zero references, a regeneration value for the software to use when it assembles the model, and limits on the allowed motion of the connections.
Creating special connections—Create cam-follower connections by selecting geometric entities on your model, with no need to create special cam geometry.
Creating kinematic gear pairs—The gear pair connections constrain the relative velocity of the selected motion axes. You do not need to create special gear geometry.
Simulating impact—You can define a coefficient of restitution for cam-follower connections to simulate impact behavior upon contact. You can define a coefficient of restitution for motion axes with limits to simulate impact when they reach the limits.
Simulating friction—You can define static and dynamic friction coefficients for cam-follower connections and motion axes to simulate friction losses.