Statements for Adding Tires to Your Model based on the GFORCE - DIFF method
Statement types: | Purpose in dataset: |
|---|
MARKER (3) | ■Wheel center marker - Identify the wheel part, the wheel center location and orientation, and the location for applying tire force movements. Use as the GFORCE I marker. ■Road floating marker - Identify the road part to the GFORCE for applying reaction forces. Use as the GFORCE JFLOAT marker. ■Road reference marker - Identify the origin and orientation of the road. Use as the GFORCE RM marker. You must locate and orient the MARKER statements as described in MARKER Locations and Orientations. |
GFORCE (1) | Apply the tire force and moments to the wheel part. |
DIFF (2) | Integrate internal tire states for lag effects. |
REQUEST (Up to 11) | Output tire kinematics and forces (longitudinal slip, slip angle, camber angle, contact patch forces, and moments). For more information, see Performing Simulations and Viewing Results. |
STRING (5) | Identify the tire property file, road property file, and other miscellaneous information. Note: The STRING for "contact type" is required for Adams to correctly create the STI tire, but it does not change the contact method, which is based entirely on the road model. |
ARRAY (1) | Holds the IDs of the GFORCE, DIFF, and STRING statements. |
MARKER Locations and Orientations
Marker statements required in dataset: | Location and orientation: |
|---|
Wheel center marker | Because the tire applies forces to the wheel center marker, you must define the wheel center so that it belongs to the wheel part and is located at the wheel center. You orient the wheel center as follows: ■x-axis lies in the wheel plane and points in the forward direction of the wheel. ■y-axis is defined as the spin-axis of the wheel. ■z-axis lies in the wheel plane and is orthogonal to the x-axis and y-axis. |
Road floating marker | The tire applies the reaction forces to the road floating marker. The road floating marker must belong to the road part, usually ground, and must be defined as FLOATING. Because the marker floats, you do not enter a location or orientation. |
Road reference marker | The road reference marker gives the location and orientation of the road. You define the road reference marker so that it belongs to the road part, usually ground. In addition, the road reference marker’s z-axis must be directed upward, meaning the z-axis is parallel to, but points in the opposite direction of, the gravity vector. Locations of the points on the road contained in the road property file are given relative to this marker. Generally, the road reference marker should be located on the road surface and below the wheel center by approximately the static loaded radius of the tire. |
Example Dataset
This section gives you an example dataset fragment that includes a complete set of statements for a single tire. The example is based on the following assumptions:
■PART/21 is the wheel and PART/99 is ground.
■The orientations assume that the ground part's x-axis points towards the rear of the vehicle, the y-axis points towards the right side of the vehicle, and the z-axis points upward.
! adams_view_name='wheel_center_marker'
MARKER/1
, PART=21
, QP = 0,0,0
, REU = 180D, 0D, 0D
!
adams_view_name='road_floating_marker'
MARKER/2
, PART = 99
, FLOATING
!
adams_view_name='road_reference_marker'
MARKER/3
, PART = 99
! adams_view_name='tire_forces'
GFORCE/1
, I = 1
, JFLOAT = 2
, RM = 3
, FUNCTION = USER(900,1,100)/
, ROUTINE=abgTire::gfo900
!
adams_view_name='tire_force_dif1'
DIFF/2
, IC = 0
, FUNCTION = USER(900,1,100)/
, ROUTINE=abgTire::dif900
!
adams_view_name='tire_force_dif2'
DIFF/3
, IC = 0
, FUNCTION = USER(900,1,100)/
, ROUTINE=abgTire::dif900
!Map for GFORCE/DIFF USER Functions:
!-----------------------------------
!par(1): dispatcher branch for tire request (always 900).
!par(2): tire GFORCE statement id.
!par(3): tire ARRAY statement id.
!
adams_view_name='tire_input_array'
ARRAY/100
,IC
,SIZE=9
,NUM= 2, 3, 1, 99, 100, 101, 102, 103, 0
!array[ 1] : 1st DIFF statement id
!array[ 2] : 2nd DIFF statement id
!array[ 3] : side flag (0 left, 1 right)
!array[ 4] : tire_minor_role STRING id
!array[ 5] : tire_property_file STRING id
!array[ 6] : simulation_type STRING id
!array[ 7] : road_property_file STRING id
!array[ 8] : road_contact_type STRING id
!array[ 9] : RIGID_WHEEL Radius (SUSPENSION analysis tire only)
!
adams_view_name='tire_rolling_states'
REQUEST/1,
, FUNCTION = USER(902,1,1)
!
adams_view_name='tire_kinematic_states_ISO'
REQUEST/2,
, FUNCTION = USER(902,2,1)
!
adams_view_name='tire_forces_contact_patch_ISO'
REQUEST/3,
, FUNCTION = USER(902,3,1)
!Map for REQUEST USER Functions:
!-------------------------------
!par(1) = branch for tire request (always 902).
!par(2) = reqtyp = {1,2,3,4,5,6,7.8.9.10,11}
!par(3) = tire GFORCE statement id.
!String Statements Description of use:
!------------------
!
! adams_view_name='tire_minor_role'
! Used by Adams Car to determine minor role (for example, FRONT or REAR).
STRING/99
,S=front
! adams_view_name='tire_property_file'
! Used by TYRxxx routines. Name of tire property file including full path that
! contains tire data or 'RIGID_WHEEL' for use in a suspension analysis.
STRING/100
,S=mdi_tire01.tir
!
adams_view_name='simulation_type'
! Used by Adams Car to determine analysis to be performed one of
'VEHICLE_HANDLING_DYNAMIC'
or 'SUSPENSION'
STRING/101
,S=VEHICLE_HANDLING_DYNAMIC
!
adams_view_name='road_property_file'
! Used by ARCxxx routines. Name of road property file including full path that
! contains road data or 'BEDPLATE' for a flat, rigid road used
! with suspension analysis.
STRING/102
,S=example_2d_flat.rdf
! adams_view_name='road_contact_type'
! handling/durability
!
STRING/103
, STRING =handling