Constraints

You define how your parts move by setting up constraints. Constraints specify how rigid bodies are connected and how they move relative to each other. By default, constraints in COSMOSMotion are idealized in that they are infinitely rigid, do not have mass, and do not have any clearances or slop. There are several types of constraints in COSMOSMotion:

• Joints are used to constrain the relative motion of a pair of rigid bodies by physically connecting them.

• Joint Primitives are used to enforce standard geometric constraints.

• Cam constraints are used to simulate Contact between a point and a curve or between two curves. Intermittent curve-curve and 3D contacts are included in this group, but do not impose fixed degrees of freedom between parts (only forces between the bodies).

• Couplers are used to provide proportional movement between translational and/or rotational movements on revolute, cylindrical, and translational joints.

• Motion is used to apply enforced movement on parts in specific degrees of freedom. This differs from applying motion on a joint, in that you are required to define the orientation of the motion (instead of using the joint orientation and freedoms).

Constraints and applied loads are associated with the geometry that is used to define them. In other words, if a joint origin is defined by an endpoint of an edge, and if that endpoint is moved because of a modification made to the geometry, then the joint moves with that endpoint.

You can use a global setting to make the basic joints flexible instead of rigid. You make joints flexible through the Simulation tab.

Learn about making joints flexible.

 The association between SolidWorks and COSMOSMotion is unidirectional. Any changes to the COSMOSMotion constraints or applied loads are not transferred to the SolidWorks geometry.