Creo Simulate > Modeling Structure and Thermal Problems > Connections > Fasteners > About Fasteners > Rotation and Separation in Fasteners
Rotation and Separation in Fasteners
When you define a fastener, you need to prevent unwanted movement about the fastener. You can choose how you want to eliminate unwanted degrees of freedom in your model:
Rotation—You should prevent the fastened components from rotating relative to each other about the bolt or screw axis. You can prevent rotation by creating constraints that eliminate all rotational degrees of freedom in the fastened components, adding more fasteners, or other means.
Separation—In the real world, fasteners do not cause components to interpenetrate. To ensure that the Creo Simulate solver does not treat the parts as interpenetrating you must establish separation between the components using one of the following methods:
Defining contact interfaces between the components. This method is the most accurate, but requires substantially more solver time.
Allowing Creo Simulate to automatically define standard fastener separation when you create a fastener. While this method yields faster solution times, it does not allow the components to separate even if they would naturally do so.
If you do not enforce separation using one of these methods, the components are likely to interpenetrate each other.
Note that, for fasteners that use point references, you do not need to specify anything in the fastener definition to ensure proper separation. For these fasteners, Creo Simulate assumes that there should be an enforced separation between the fastened components, and uses a contact, if present, or standard fastener separation to prevent interpenetration.
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