12. Dynamic Relaxation

Dynamic Relaxation is the conventional means of finding static solution in explicit transient simulations. In CMUT models this technique is used during the Bias phase, and also the pre-stress and/or atmospheric loading phase if required. By effectively placing frequency dependent damping on all the nodes, the solution can be forced to equilibrium much faster. In addition, the dynamic relaxation conditions can be altered during runtime to allow the users to run both static and dynamic phases in a single simulation. 
Typically the default settings in OnScale are more than adequate, although sometimes the user may wish to tweak these a little to enhance a desired effect in the model, for example membrane 'bounce' as it hits the contact elements.

/* Turn on Dynamic Relaxation for Bias/static phase
/* NOTE: DRLX AUTO works fine, but by tweaking a little you can get the membrane to 'bounce'

c drlx auto 0.5 * 0.01
symb w = 2 * $pi * $freqint drlx auto2 $w

After Static phase has finished:

/* Turn off Dynamic Relaxation for active calculation
drlx 0.0