*PointToSurfaceJoint()

Creates a point-to-surface high-pair joint with three rotational degrees of freedom and two translational degrees of freedom.

Syntax

*PointToSurfaceJoint(ptsf_name,"ptsf_label",body_1, body_2, point, surface, ref_marker, [icm], [ALLOW_COMPLIANCE])

Arguments

ptsf_name: The variable name of the point-to-surface joint.; Data type: varname
ptsf_label: The label of the point-to-surface joint.; Data type: label
body_1: The first body constrained by the point-to-surface joint.; Data type: Body
body_2: The second body constrained by the point-to-surface joint.; Data type: Body
point: The point on body_1 that is constrained to the surface on body_2.; Data type: Point
surface: The surface on body_2 which is constrained to the point on body_1.; Data type: Surface
ref_marker: Reference marker to which the surface points are defined.; Data type: Marker
icm: An optional argument for the reference marker of the initial condition information for the contact point. If not used, initial condition information is defined with respect to the reference marker.; Data type: Marker
ALLOW_COMPLIANCE: An optional argument that indicates the joint can be made compliant.

Example

*BeginMDL(the_model, "Example PointToSurfaceJoint")

 *Marker(mrk_0, "Ref marker for the point")
 *Marker(mrk_1, "Ref marker for the surface")
 *Marker(mrk_2, "ICM marker 1")
 *Body(bd_0, "First Body")
 *Body(bd_1, "Second Body")
 *Point(p_0, "Point on body 1")
 *Surface(surf_1, "Surface on body 2", UOPEN, VOPEN)
 *PointToSurfaceJoint(ptsf_0, "ptsf", bd_0, bd_1, p_0, surf_1, mrk_0, mrk_1)

*EndMDL()

Context

*BeginMdl()

*DefineAnalysis()

*DefineSystem()

Properties

Table 1.
Property	Returns Data Type	Description
b1	Body	The first body constrained by the point-to-surface joint.
b2	Body	The second body constrained by the point-to-surface joint.
i	Marker	The "i" marker in the case of a compliant joint.
icm	Marker	The optional reference marker for the initial conditions of the point of contact.
ic_use_xyz	boolean	Denotes if the displacement initial conditions are to be used for the point of contact on body_1 (TRUE or FALSE).
ic_x_disp	real	The value of the initial displacement of the point of contact in the icm x direction. This is applied during the assembly phase of the solver.
ic_y_disp	real	The value of the initial displacement of the point of contact in the icm y direction. This is applied during the assembly phase of the solver.
ic_z_disp	real	The value of the initial displacement of the point of contact in the icm z direction. This is applied during the assembly phase of the solver.
id	integer	Solver input deck identification number.
id_string	string	The ID represented as a string.
isbush	boolean	See Comments below.
label	string	The descriptive label of the point-to-surface joint.
j	Marker	The "j" marker in the case of a compliant joint.
jfloat	Marker	The floating marker on body two.
joint_i	Marker	The "i" marker for the non-compliant joint.
joint_j	Marker	The "j" marker for the non-compliant joint.
note	string	The note on the entity.
num	integer	The unique identification number within MDL.
origin	point	The point on body one which is constrained to body two.
rm	Marker	The reference marker of the surface.
state	boolean	Control state (TRUE or FALSE). This parameter is read only and cannot be directly changed by the user (see user_state).
surf	Surface	The surface on body 2 which is constrained to body 1.
type	string	The unique joint type.
user_state	boolean	The state that can be set by the user (TRUE or FALSE).
varname	string	The variable name of the point-to-surface joint.

Comments

The point-to-surface joint provides five degrees of freedom: three rotational at the instantaneous point of contact and two translational DOF.

The ALLOW_COMPLIANCE argument is optional. When it is included, it indicates that the joint can be made compliant. In compliant mode, such a joint acts as a bushing.

The "isbush" property is valid only for joints that can be made compliant. When "isbush" is set to FALSE, the joint acts like a kinematic joint (in noncompliant mode). When "isbush" is set to TRUE, the joint acts like a bushing (in compliant mode).

When the compliant option in a system is switched to "non-compliant", all the joints in the system act as kinematic joints. However, when the system option is switched to "compliant", only the joints that are created with an ALLOW_COMPLIANCE flag act as bushings. The rest of the joints continue to behave as kinematic joints.