FreqBushing - Entity

The Altair Bushing Model, also known as a FreqBushing entity in MotionView, is a sophisticated model that you can use to simulate the behavior of bushings in vehicle dynamics, durability and NVH simulations.

Connect a FreqBushing from the Entity Editor

Connections define the two connecting bodies, the point where the forces act, and the marker that defines the bushing orientation. Bodies, markers, and points can be selected either graphically or through the Model Browser.

From the Selector tab, select the first body to connect.
The I marker of the Force_field statement in the solver deck lies on Body 1, is located at Point 1, and has the orientation of Marker.
- Click Body 1 and select a body from the modeling window.
- Double click Body 1 and select the required body from the dialog.
Similarly, select the second body to connect by clicking the Body 2 input collector.
The J marker of the Force_field statement in the solver deck lies on Body, is located at Point 1, and has the orientation of Marker.
Select a point to locate the bushing. The point defines the location where the bushing forces act. The I marker and the J (floating) marker of the Force_field statement are at Point 1.
- Click Point 1 and select a point from the modeling window.
- Double click Point 1 and select the required point from the dialog.
Select a marker to orient the bushing in space.
- Click Marker and select a marker from the modeling window.
- Double click Marker and select the required marker from the dialog.
All three axes of the bushing are along the axes of the respective axes of the Marker (X-X,Y-Y,Z-Z).
Tip: Click Edit File to edit and save the bushing property file.

TeimOrbit FreqBushing File

A sample TeimOrbit FreqBushing text file is shown below.

$-----------------------------------------------------------HEADER
[HEADER]
FILE_TYPE     = 'gbs'
FILE_VERSION  = '1.1'
FILE_FORMAT   = 'ASCII'
$------------------------------------------------------------UNITS
[UNITS]
TIME   = 'Sec'
LENGTH = 'MM'
FORCE  = 'Newton'
ANGLE  = 'Degree'
MASS   = 'Kg'
$------------------------------------------------------------GLOBAL
[GLOBAL]
 EPSILON = 1.0000000000000001E-005
 COUPLING = 'Uncoupled'
$------------------------------------------------------------DIRECTIONS
[DIRECTIONS]
(ACTIVITY)
{   Formulation          FX   FY   FZ   TX   TY   TZ  }
'SPLINE_STIFFNESS'        1    0    0    0    0    0
'CUBIC_STIFFNESS'         0    0    0    0    0    0
'CONSTANT_STIFFNESS'      0    1    1    1    1    1
'CONSTANT_DAMPING'        0    1    1    1    1    1
'RUBBER_DAMPING'          1    0    0    0    0    0
'HYDROMOUNT_DAMPING'      0    0    0    0    0    0
$----------------------------------------------------SPLINE_STIFFNESS_FX
[SPLINE_STIFFNESS_FX]
(SPLINE_DATA)
{       disp        force}
    -2.10000 -10120.00000 
    -2.05000  -9120.00000 
    -2.00000  -8240.00000 
    -1.90000  -7060.00000 
    -1.80000  -5256.96000 
    -1.70000  -4376.96000 
    -1.65000  -3611.56000 
    -1.50000  -3169.57000 
    -1.45000  -2464.31000 
    -1.35000  -2070.31000 
    -1.15000  -1967.72000 
    -1.10000  -1656.96000 
    -1.00000  -1151.96000 
     0.00000      0.00000 
     1.00000   1070.00000 
     1.10000   1441.00000 
     1.70000   1730.00000 
     2.00000   1868.50000 
     2.50000   2493.04000 
     2.90000   2803.04000 
     3.00000   3163.04000 
     3.15000   3323.04000 
     3.40000   3483.04000 
     3.65000   3593.04000 
     3.80000   3623.04000 
     3.90000   4443.04000 
     4.05000   5103.04000 
     4.15000   5300.00000 
     4.40000   5800.00000 
$------------------------------------------------------RUBBER_DAMPING_FX
[RUBBER_DAMPING_FX]
 NPRELOADS  = 1
(PRELOAD_1)
 PRELOAD   = 0.0000000000000000E+000
 R         = 1.0984344869354972E+000
 K0        = 2.1291366586210524E+003
 K1        = 2.0003149481217424E+004
 K2        = 5.7832750782252319E+001
 C0        = 3.7031090214294602E+002
 C1        = 3.3917669230363902E+002
 C2        = 5.3050041580213869E-001
 P0        = 5.0820696402844403E+000
 P1        = -4.4259813439671127E+000
 P2        = 1.3941895515214624E-002
 Q0        = 1.6145231637586410E+000
 Q1        = -2.1513678904349827E+000
 Q2        = 7.0174362438161719E-001
$-----------------------------------------------------CUBIC_STIFFNESS_FX
[CUBIC_STIFFNESS_FX]
 OF = 0.0000000000000000E+000
 O = 0.0000000000000000E+000
 OS = 1.1030899999999999E+003
 Rp = 2.2000000000000002E+000
 Rn = -1.0500000000000000E+000
 Ep = 4.4000000000000004E+000
 En = -2.1000000000000001E+000
 RnF = -1.4044600000000000E+003
 RpF = 2.1183200000000002E+003
 EnS = 2.0600000000000000E+004
 EpS = 2.0600000000000000E+004
$--------------------------------------------------CONSTANT_STIFFNESS_FX
[CONSTANT_STIFFNESS_FX]
 k = 1.1030899999999999E+003
$----------------------------------------------------CONSTANT_DAMPING_FX
[CONSTANT_DAMPING_FX]
 c = 1.1030000000000000E+000
$--------------------------------------------------CONSTANT_STIFFNESS_FY
[CONSTANT_STIFFNESS_FY]
 k = 1.0000000000000000E+003
$----------------------------------------------------CONSTANT_DAMPING_FY
[CONSTANT_DAMPING_FY]
 c = 1.0000000000000000E+000
$--------------------------------------------------CONSTANT_STIFFNESS_FZ
[CONSTANT_STIFFNESS_FZ]
 k = 1.0000000000000000E+003
$----------------------------------------------------CONSTANT_DAMPING_FZ
[CONSTANT_DAMPING_FZ]
 c = 1.0000000000000000E+000
$--------------------------------------------------CONSTANT_STIFFNESS_TX
[CONSTANT_STIFFNESS_TX]
 k = 8.0000000000000000E+002
$----------------------------------------------------CONSTANT_DAMPING_TX
[CONSTANT_DAMPING_TX]
 c = 8.0000000000000000E+000
$--------------------------------------------------CONSTANT_STIFFNESS_TY
[CONSTANT_STIFFNESS_TY]
 k = 8.0000000000000000E+002
$----------------------------------------------------CONSTANT_DAMPING_TY
[CONSTANT_DAMPING_TY]
 c = 8.0000000000000000E+000
$--------------------------------------------------CONSTANT_STIFFNESS_TZ
[CONSTANT_STIFFNESS_TZ]
 k = 8.0000000000000000E+002
$----------------------------------------------------CONSTANT_DAMPING_TZ
[CONSTANT_DAMPING_TZ]
 c = 8.0000000000000000E+000
[FIT_REPORT]
 FIT_REPORT_NAME = 'sample_gbs.pdf'

Subroutine Definition

GSE Subroutine

Input Parameters

The Freq Bushing subroutine is defined in the AltairBushingMotionSolve.dll (.so) with GSESUB_BW function name.

GSE subroutine input user string:

usrsub_param_str="USER(P₁,P₂,P₃,P₄,P₅,P₆,P₇)"


Parameter	Description
`P₁`	Freq Bushing property file name solver string ID (.gbs)
`P₂`	Preload array ID
`P₃`	Offset array ID
`P₄`	Displacement scale array ID
`P₅`	Force scale array ID
`P₆`	Unused
`P₇`	Mount Limits array ID

CSE Definition Block in the xml

<Control_StateEqn
     id                  = "303001"
     type                = "USERSUB"
     num_state           = "24"
     num_output          = "6"
     u_solver_array_id   = "30300300"
     x_solver_array_id   = "30300100"
     y_solver_array_id   = "30300200"
     usrsub_param_string = "USER(303001,30300400,30300500,30300600,30300700,0,-30301300)"
     usrsub_dll_name     = "AltairBushingMotionSolve"
     usrsub_fnc_name     = "GSESUB_BW"
     usrsub_der1_name    = "GSEXX_BW"
     usrsub_der2_name    = "GSEXU_BW"
     usrsub_der3_name    = "GSEYX_BW"
     usrsub_der4_name    = "GSEYU_BW"
     is_static_hold      = "FALSE"
  />

Mount Subroutine

Input Parameters

The Freq Bushing Mount subroutine is defined in the AltairBushingMotionSolve.dll (.so) with GSESUB_MOUNT function name.

GSE subroutine input user string:

usrsub_param_str="USER(P₁,P₂)"


Parameter	Description
`P₁`	Stiffness coefficients array ID
`P₂`	Damping coefficients array ID

CSE Definition Block in the xml

<Control_StateEqn
     id                  = "303002"
     type                = "USERSUB"
     num_state           = "6"
     num_output          = "12"
     u_solver_array_id   = "30301200"
     x_solver_array_id   = "30301000"
     y_solver_array_id   = "30301100"
     usrsub_param_string = "USER(30300800,30300900)"
     usrsub_dll_name     = "AltairBushingMotionSolve"
     usrsub_fnc_name     = "GSESUB_MOUNT"
     usrsub_der1_name    = "GSEXX_MOUNT"
     usrsub_der2_name    = "GSEXU_MOUNT"
     usrsub_der3_name    = "GSEYX_MOUNT"
     usrsub_der4_name    = "GSEYU_MOUNT"
     is_static_hold      = "FALSE"
  />

Friction Subroutine

Input Parameters

The Freq Bushing Friction subroutine is defined in the AltairBushingMotionSolve.dll (.so) with Gsesub_Friction function name.

GSE subroutine input user string:

usrsub_param_str="USER(P₁)"


Parameter	Description
`P₁`	Friction parameters array ID

<Control_StateEqn
     id                  = "303003"
     type                = "USERSUB"
     num_state           = "2"
     num_output          = "3"
     u_solver_array_id   = "30302200"
     x_solver_array_id   = "30302000"
     y_solver_array_id   = "30302100"
     usrsub_param_string = "USER(-30302300)"
     usrsub_dll_name     = "AltairBushingMotionSolve"
     usrsub_fnc_name     = "Gsesub_Friction"
     usrsub_der1_name    = "Gsexx_Friction"
     usrsub_der2_name    = "Gsexu_Friction"
     usrsub_der3_name    = "Gseyx_Friction"
     usrsub_der4_name    = "Gseyu_Friction"
     is_static_hold      = "FALSE"
  />