Directions Block
The Directions block selects what force formulations the simulation model uses for
each force and torque direction. This is a mandatory block. The block contains a
table where each row is a force method and each column a force or torque direction.
To select or turn on a force formulation for a given force direction, enter
1
in the corresponding row and column. To turn off a force
method for a given force direction, enter 0
(zero).
Parameter  Type  Units  Description 

ACTIVITY  Subblock    This subblock is specified as
(ACTIVITY) 
FORMULATION  String    Valid choices are:

FX  Integer    Valid choices are:

FY  Integer    
FZ  Integer    
TX  Integer    
TY  Integer    
TZ  Integer   
Some of the formulations are mutually exclusive and some of the formulations can be added in parallel.
 Each force direction (one column in the matrix below) can contain only one stiffness model and one damping model.
HYDROMOUNT_DAMPING
can be used for one translational direction ONLY. Because the software does not impose this limitation, understanding the impracticality of fitting more than one hydromount per attachment is important. Where
HYDROMOUNT_DAMPING
is used (for FX, FY, FZ), theRUBBER_DAMPING
for the same direction CANNOT be used. CONSTANT_STIFFNESS
,SPLINE_STIFFNESS
andCUBIC_STIFFNESS
are mutually exclusive.
In the following example, the stiffness models are shown in blue and damping models in green.
 For FX:
SPLINE_STIFFNESS
andRUBBER_DAMPING
are active.  For FY:
CONSTANT_STIFFNESS
andHYDROMOUNT_DAMPING
are active.  For FZ:
CONSTANT_STIFFNESS
andCONSTANT_DAMPING
are active.  For TX:
CUBIC_STIFFNESS
andCONSTANT_DAMPING
are active.  For TY:
CONSTANT_STIFFNESS
andCONSTANT_DAMPING
are active.  For TZ:
SPLINE_STIFFNESS
andRUBBER_DAMPING
are active.
$$ DIRECTIONS
[DIRECTIONS]
(ACTIVITY)
{ formulation FX FY FZ TX TY TZ }
'SPLINE_STIFFNESS' 1 0 0 0 0 1
'CONSTANT_STIFFNESS' 0 1 1 0 1 0
'CUBIC_STIFFNESS' 0 0 0 1 0 0
'CONSTANT_DAMPING' 0 0 1 1 1 0
'RUBBER_DAMPING' 1 0 0 0 0 1
'HYDROMOUNT_DAMPING' 0 1 0 0 0 0
The net force output for any direction is the sum of the forces due to the active force formulations in that direction.