*ParallelAxesJointPair() - parallel axes joints (normal)

Creates a parallel axes joint pair with its axes parallel to normal defined by a point or vector.

Syntax

*ParallelAxesJointPair(joint_name,"joint_label",body_1, body_2, origin, NORMAL, POINT|VECTOR, point|vector)

Arguments

joint_name
The variable name of the parallel axes joint pair.
Data type: varname
joint_label
The descriptive label of the parallel axes joint pair.
Data type: label
body_1
The first body or body pair constrained by the parallel axes joint pair.
Data type: Body or BodyPair
body_2
The second body or body pair constrained by the parallel axes joint pair.
Data type: Body or BodyPair
origin
The location(s) of the parallel axes joint pair of body_1.
Data type: Point or PointPair
NORMAL
A required argument when a point, point pair, vector, or vector pair is used to define the axes of the joint pair.
POINT|VECTOR
A keyword that indicates the alignment method.
point|vector
An entity variable referring to a Point, PointPair, Vector, or VectorPair which is based on the above keyword.
Data type: Point, PointPair, Vector, or VectorPair

Example

*BodyPair(body_1,     "First body",       p_1)
*BodyPair(body_2,     "Second body",      p_2)
*PointPair(point_1,   "CM of first body")
*VectorPair(v_Z,      "Global Z")
*ParallelAxesJointPair(j_paraxes, "Parallel axes joint", body_1, 
                                                         body_2, 
                                                         point_1, 
                                                         NORMAL, 
                                                         VECTOR, 
                                                         v_Z)

Context

*BeginMdl()

*DefineAnalysis()

*DefineSystem()

Properties

Table 1.
Property Returns Data Type Description
b1 BodyPair The first body pair constrained by the parallel axes joint pair.
b2 BodyPair The second body pair constrained by the parallel axes joint pair.
i MarkerPair The marker pair on b1.
j MarkerPair The marker pair on b2.
l PlanarJoint Left parallel axes joint.
label string The descriptive label of the parallel axes joint pair.
r PlanarJoint Right parallel axes joint.
state boolean Control state (TRUE or FALSE).
varname string The variable name of the parallel axes joint pair.

Comments

The individual joints of a *ParallelAxesJointPair() can be referred to as joint_name.l (left parallel axes joint) and joint_name.r (right parallel axes joint).

A parallel axes joint pair constrains the relative rotation between two body pairs such that the two axes pairs always stay parallel. The axes may be defined by either specifying a point or vector (using the NORMAL flag for the sixth argument) or specifying two points or vectors that lie in the plane normal to the axes (using the INPLANE flag for the sixth argument).

When a point is used (instead of a vector) to define an axis, it is obtained as the direction from the origin of the joint to the specified point.