Link Geometries

Description

This element defines the track link geometry. The x, y, and z axes define a local reference frame for a track link. The x-axis is longitudinal to the driving direction, the y-axis is lateral, and the z-axis is normal to the plane spanned by the x- and y-axes. Keep the direction of the z coordinate as shown in the figure below. Keep the reference coordinate system parallel to the CG coordinate system. The CG coordinate system is defined in the MotionView model. You can choose the location of the reference frame origin.
Note: The lateral locations of the origin of all systems and points are in the middle of the track-link.

For soil contact, define the contact points. The number of points depends on the shape of the link. It is recommended not to exceed three points. The maximum points allowed in the model is five. The scheme of a track-link with three typical contact points is shown in this figure. The track links with 2, 3 and 5 contact points are shown in this figure.

Parameters

WIDTH
(REAL)
The width of the track links.
If WIDTH<0, the width is WIDTH=WIDTHTB*|WIDTH|. WIDTHTB is defined in General Data - Part 1.
N_CP
The number of contact points.
1≤N_CP≤5.
The recommendation is 1≤N_CP≤3.
WID_OR_MIN
Definition of Bekker parameter b (see appendix A).
1≤WID_OR_MIN≤2.
If WID_OR_MIN=1, b is the width of the track.
If WID_OR_MIN=2, b is a minimum dimension in a link.
WID_OR_MIN=1 is the recommended value.
HEIGHTi
(REAL)
Height related to point I.
1≤i≤N_CP. For details see the figure below.
LENGTHAi
(REAL)
Length related to point i, 1≤i≤N_CP. For details, see the figure below.
LENGTHBi
(REAL)
Length related to point i, 1≤i≤N_CP.
For details, see figure below.
If 0>LENGTHBi, then LENGTHBi = LENGTHAi*|LENGTHBi |.
If HEIGHTi=0, LENGTHBi is the unused parameter. The range is: LENGTHAi*1.5 ≥LENGTHBi≥ LENGTHAi/2.
If LENGTHBi is out of the range, the new value is LENGTHBi=LENGTHAi
XC, ZC
(REAL)
X and Z components of a vector in the reference coordinate system to the center of mass of each link. For details, see the figure below.
Xi, Zi
(REAL) – X and Z components of a vector in the reference coordinate system to point i. For details, see the figure below.


Figure 1. Scheme of a track link with three typical contact points. x, z – coordinate system of the link body. Note that the C. G. coordinate system should be parallel to the body coordinate system.


Figure 2. Track links: (a) link with one grouser and two contact points, (b) link with two grousers and three contact points, and (c), link with three grousers and five contact points.