Damping stabilization factors

Hi Farzin,

use NLADAPT>STABILIZ and refer this load collector in the loadstep definition. This is a static stabilization based on viscous damping, where the viscous forces are added to the equilibrium equations.  The large displacement analysis may cause additional difficulty in convergence because of the geometric nonlinearity. STABLIZ parameter in NLADAPT may help.  With this parameter present, OptiStruct will apply some stabilization or damping force on the model. This is especially helpful if some buckling happens under the load.  However, the stabilization effort introduces an artificial error to the simulation, which should be minimized. It is recommended to monitor the ratio of stabilization energy over internal energy in the .nlm output file. A ratio smaller than 1% is ideal.