What are the key considerations for surface-to-surface contact?

Surface-to-surface contact in Abaqus is a discretization method that enhances the accuracy and stability of contact simulations by better enforcing contact constraints across interacting surfaces. Unlike node-to-surface contact, it uses the average positions of slave nodes to calculate constraints, reducing issues like stress irregularities and unrealistic penetration. Key considerations for surface-to-surface contact include:

Master-slave relationship

• Ideally, the slave surface should belong to the smaller, softer body with higher element density.
• The master surface should be assigned to the stiffer body with a coarser mesh. This setup ensures accurate stress distribution and avoids issues like master nodes passing through the slave surface.

Mesh density

• A finer mesh on the slave surface improves accuracy by better capturing stress gradients and ensuring proper constraint enforcement.
• Coarse slave meshes can lead to longer processing times and inaccurate results, as seen in cases where edge loads are not properly captured.

Stress distribution

• Surface-to-surface contact reduces stress artifacts compared to node-to-surface methods. However, high-stress regions (e.g., edge loads) are still influenced by the master-slave relationship and mesh quality.

Efficiency

• While surface-to-surface contact is more robust than node-to-surface contact, adhering to correct master-slave assignments further improves computational efficiency and result reliability.

Best practices

• Use surface-to-surface contact over node-to-surface whenever possible for more accurate results.
• Prioritize assigning the slave surface to the smaller body with higher mesh density if all criteria cannot be met.
• Perform sensitivity analyses to validate that your mesh density and master-slave definitions yield stable results.