Product: Abaqus/Standard
Benefits: A common modeling technique in the field of rotordynamics is to use unsymmetric stiffness and damping matrices to model fluid film bearings supporting a rotating structure. Abaqus/Standard now supports frequency-dependent unsymmetric linear coupled stiffness and viscous damping matrices to model fluid film bearings in rotordynamic analyses.
Description: For the unsymmetric linear coupled stiffness case you define the spring stiffness matrix components, 
, which are used in the equation
is the force in the 
component of relative motion, 
is the motion of the 
component, and is the coupling between the and components. For the unsymmetric linear coupled viscous damping case you define the damping coefficient matrix components, 
, which are used in the equation 
is the force in the component of relative motion, 
is the velocity in the component, and is the coupling between the and components. References: