Model Element

Description

The Constraint_PTdSF element constrains a fixed point on a body to slide along a surface that passes through the origins of a specified set of markers.  These markers may belong to different bodies.  As the markers move in space, the surface is calculated at every time step using CUBIC spline interpolation through the marker origins.  Hence, the surface deforms as the markers move about.

Format

<Constraint_PTdSF

    id                   = "integer"

  [ label                = "string" ]

    i_marker_id          = "integer"

    ref_dsurface_id      = "integer"

/>

Attributes

id

Element identification number, (integer>0).  This number is unique among all Constraint_PTdSF elements.

label

The name of the Constraint_PTdSF element.

i_marker_id

Specifies a Reference_Marker whose origin defines the point that is constrained to move along the deformable curve.

ref_dsurface_id

Specifies the deformable surface used to define the Constraint_PTdSF element.

Comments

If the current u or v value goes out of this range, MotionSolve will hold the u or v value at the boundary until the point falls back in range of the deformable surface.  However, this may lead to incorrect results.  You are encouraged to check the results for correctness in such a situation.  For more information, please refer to the
Reference_DeformSurface model element.

Example

<Reference_DeformSurface

    id                  = "1"

    end_type            = "NATURAL"

    num_marker_row      = "7"

    num_marker_col      = "7">

30101490 30101500 30101510 30101520 30101530 30101540 30101540

30101420 30109781 30113791 30117801 30121811 30125821 30101480

30101350 30108711 30112721 30116731 30120741 30124751 30101410

30101120 30102061 30103071 30104081 30105091 30106101 30101130

30101140 30110571 30114581 30118591 30122601 30126611 30101200

30101210 30111641 30115651 30119661 30123671 30127681 30101270

30101280 30101290 30101300 30101310 30101320 30101330 30101340

 </Reference_DeformSurface>

 <Constraint_PTdSF

    id                  = "1"

    i_marker_id         = "30107780"

    ref_dsurface_id     = "1"

 />    

 <Post_Graphic

    id                  = "500000"

    type                = "DeformSurface"

    surface_id          = "1"

    nseg_u              = "30"

    nseg_v              = "30"

 />

Model Element

Description

PTDSF defines a constraint of a point to a deformable surface.  This is an instance of a higher pair constraint.

Declaration

def PTDSF(id, LABEL=””, I= , DSURFACE= ):

Attributes

id

Element identification number (integer>0).  This number is unique among all PTDSF elements.

LABEL

The name of the PTDSF element.

I

Defines the marker ID of the point.

DSURFACE

Defines the ID of the deformed surface.

Comments

See Constraint_PTDSF

Example

The example below shows a definition of a PTDSF.

PTDSF(1, I=30107780, DSURFACE=1)