1. The Phenomenon Touchdown Behaviour:
High compression
Multiple small radius bends
Fatigue life reduction
OrcaFlex can model this if sufficient segmentation is present

2. Insufficient Segmentation
Observed Behaviour:
High compression
Single large radius bend in response
Segment Euler Limit acceptable F = p2 EI / L2
How do we diagnose that the segmentation is insufficient?

3. Diagnosing Insufficient Segmentation
Checklist:
Are there high compressions?
Is the Segment Euler Limit infringed?
Does curvature range plot show small local bends?
Does instantaneous tension range show “violent” variation?
Refine segmentation and check for response change
Extra 2D Model Check:
Is all loading perfectly in plane?
Check with Out-of-Plane “Trigger”