CONTACT RECOMMENDATION ALTER DEFAULT SETTING


When creating surface-to-surface contact elements, ANSYS has been configured to initiate its contact 
settings for best overall performance. 

However, it is always a good idea to check the most important settings before starting the solution:
 
KEYOPT(2) - Contact algorithm.
KEYOPT(5) - Automated adjustment.
KEYOPT(9) - Effect of initial penetration or gap.
KEYOPT(12) - Behaviour of contact surface.
FKN - Normal penalty stiffness factor.
 
A good alternative set of default settings would be:
 
KEYOPT(2)=1 (Use Penalty Method)
KEYOPT(5)=3 (Close gaps and reduce penetrations with auto CNOF)
KEYOPT(9)=1 (Exclude the effects of gaps or penetrations)
FKN=0.1 or 1.0
 
The Penalty Method is a good algorithm for obtaining a solution quickly, although you may need to 
rerun the solution if FKN isn't high enough. By putting KEYOPT(5)=3 and KEYOPT(9)=1, 
you tell ANSYS to analyse the components in a "just touching" condition, regardless of any relatively 
small penetrations or gaps between individual components. FKN will control how much penetration will 
occur. A value of 0.1 will work well for contact where components are being bent; a value of 1.0 will 
work well for components that are being formed or forged.