Contact Definition
Define how parts interact — from rigid bonding to frictional sliding.
If you only have 2 minutes
Define how components interact with each other — from rigid bonding to frictional sliding.
When do I need contact?
You need contact definitions whenever your model consists of multiple parts that touch or slide against each other.
Contact types
| Type | Description | | --- | --- | | Bonded (tied) | Fixed connection, no relative sliding | | Frictional | Sliding with Coulomb friction | | Frictionless | Sliding without resistance |
Start with bonded contacts — convergence is much better. Only switch to frictional contacts when it's physically necessary.
Avoiding instability
Contact instabilities are the most common cause of convergence problems in assemblies. Check:
- No initial penetration between contact surfaces
- Sufficient contact stiffness
- Correct assignment of contact surface pairs
Troubleshooting contact
If the solver fails or results look unrealistic in the contact zone, see Troubleshooting → Unstable Contact.