Blade Root Contact Modelling Best Practices
Best practices for contact modelling at blade root attachments — contact definition, friction, mesh, convergence and post-processing.
Contact definition
Use penalty-based contact with finite sliding. Define the contact pairs on all mating faces. Use a friction coefficient appropriate for the material, surface finish and temperature. The friction coefficient affects the load distribution and the fretting behaviour.
Mesh at contact
Use a fine mesh at the contact faces — the element size should be small enough to capture the contact pressure distribution. The master and slave surface meshes should be of similar density for accurate contact detection.
Convergence
Monitor the contact convergence. If convergence is difficult, use smaller load increments, automatic stabilisation or a different contact algorithm. Check for contact chattering (alternating open/close). The final contact status should be stable.
Post-processing
Check the contact pressure at each face (no separation, no excessive pressure). Check the slip amplitude for fretting. Check the load sharing between tang pairs. The total contact force should match the blade centrifugal force.