TeimOrbit 2D Road Type: drum

The rotating drum is implemented as a 2D type road. If the ROAD_TYPE is set to drum, COSIN/road searches for and reads the following data items in the [PARAMETERS] section:
Name of Input Variable Unit Meaning
diameter length Diameter of the tire test drum. COSIN/road assumes outer drum, if the diameter < 0.
x_coord_drum_center length x coordinate of drum center in global coordinates, used for all wheels.

Remark: Be sure to place the drum near the rim center, and keep the wheel's translational speed small enough not to leave the drum's zenith.

y_coord_drum_center length y coordinate of drum center in global coordinates, used for all wheels.
x_coord_drum_center_wheel_i (i = 1,2,3,..,25) length x coordinate of drum center in global coordinates, used only for wheel i (i = 1,2,3,..,25).
y_coord_drum_center_wheel_i (i = 1,2,3,..,25) length y coordinate of drum center in global coordinates, used only for wheel i (i = 1,2,3,..,25).
number_cleats - Number of extra cleats on drum (number_cleats = 0 allowed).
cleat_starting_angle angle Drum angle coordinate of 1st cleat, used for all wheels.
cleat_starting_angle_wheel_i (i = 1,2,3,..,25) angle Drum angle coordinate of 1st cleat, used only for wheel

i (i = 1,2,3,..,25).

cleat_direction angle Direction of cleat relative to drum spin axis. Direction is zero if cleat is oriented exactly in transversal direction. Direction angle is measured counter-clockwise if looking from above onto the drum surface.

Default value is 0 (transversal cleat).

curved_cleat_surface -
0
Cleat surface is flat.


Figure 1.
1
Cleat surface is curved according to drum surface curvature.


Figure 2.

Default value is 0 (flat).

flat_cleat_support -
0
Cleat is mounted on the drum such that its support on the drum surface is curved according to overall drum curvature.


Figure 3.
1
Cleat is mounted on the drum such that its support on the drum surface is flat between cleat's start and cleat's end.


Figure 4.

Default value is 0 (non-flat cleat support).

This parameter is only used and relevant if curved_cleat_surface = 0.

mu_factor_cleat - Friction modification factor on cleats.
stopper_distance length Distance between front and read stopper of drum opening. Default value is 75% of drum diameter.

The drum speed is defined by one of the following alternatives:

Either:
     
v length/time Constant rotation speed of drum surface
acceleration_time time Time span at beginning of dynamic simulation, to accelerate drum from stand-still to nominal velocity.

Default value is 0.

Or:
data sub-section (TV_DATA) Arbitrarily many lines with 2 values of type: time, length/time Data pairs defining speed-vs.-time data of the drum’s time-dependent surface speed profile. t-values (first value in each line) should be in ascending order.

The exact geometry of the cleat is defined by one of the following three alternatives:

Either:
     
cleat_height length Height of cleats.
cleat_length length Length of cleat, measured in circumferential direction of drum.
cleat_bevel_edge_length length Length of bevel edge of cleat, measured in circumferential direction of drum. Bevel edge has 45 degree slope.
cleat_edge_rounded  
0
Cleat bevel edge is flat.
1
Cleat bevel edge is rounded by a quarter circle.
Or
data sub-section (XZ_DATA) Arbitrarily many lines with data of type: 2 x length Data pairs defining x and z data of the cross section of the cleat. No rounding of edges is assumed. x values should be in ascending order. First and last y value should be zero.
Or:
data sub-section (XZR_DATA) Arbitrarily many lines with data of type: 3 x length Data triples defining x and z data of the cross section of the cleat, together with rounding radii in these data points. Rounding radii may be zero. x values should be in ascending order. First and last y value should be zero.
Optionally, the exact height geometry of the stoppers can be specified by spline data:
data sub-section (stopper_geometry) Arbitrarily many lines with data of type: 2 x length Data pairs defining x and z data of the stoppers. x values must be non-negative and ascending: x = 0 refers to the start in longitudinal direction of the stopper.