*PlanarJointPair() - planar joints (plane)

Creates a planar joint pair parallel to a specified plane.

Syntax

*PlanarJointPair(joint_name,"joint_label",body_1, body_2, origin, INPLANE, POINT|VECTOR, point_1|vector_1, POINT|VECTOR, point_2|vector_2)

Arguments

joint_name
The variable name of the planar joint pair.
Data type: varname
joint_label
The descriptive label of the planar joint pair.
Data type: label
body_1
The first body or body pair constrained by the planar joint pair.
Data type: Body or BodyPair
body_2
The second body or body pair constrained by the planar joint pair.
Data type: Body or BodyPair
origin
The location(s) of the planar joint pair.
Data type: Point or PointPair
INPLANE
A required argument when two points, two vectors, or a point and a vector are used to define the plane of the planar joint pair.
POINT|VECTOR
A keyword that indicates the alignment method.
point_1|vector_1
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
POINT|VECTOR
A keyword that indicates the alignment method.
point_2|vector_2
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 "First body", p_1)
(body_1,
*BodyPair "Second body", p_2)
(body_2,
*PointPair "CM of first body")
(point_1,
*VectorPair "Global X")
(v_X,
*VectorPair "Global Z")
(v_Z,
*PlanarJointPair(j_planar, "Planar joint", body_1, 
                                           body_2, 
                                           point_1, 
                                           INPLANE, 
                                           VECTOR, 
                                           v_X, 
                                           VECTOR, 
                                           v_Z)

Context

*BeginMdl()

*DefineAnalysis()

*DefineSystem()

Properties

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

Comments

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

A planar joint constrains two bodies so as to restrict relative motion between the two bodies to the xy plane and allow relative rotation about the z-axis only. The joint plane may be defined by either specifying the normal to the plane (using the NORMAL flag for the sixth argument) or specifying three points (or vectors) lying in the plane (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.