ObjectContactCircleCable2D

A very specialized penalty-based contact condition between a 2D circle (=marker0, any Position-marker) on a body and an ANCFCable2DShape (=marker1, Marker: BodyCable2DShape), in xy-plane; a node NodeGenericData is required with the number of cordinates according to the number of contact segments; the contact gap \(g\) is integrated (piecewise linear) along the cable and circle; the contact force \(f_c\) is zero for \(gap>0\) and otherwise computed from \(f_c = g*contactStiffness + \dot g*contactDamping\); during Newton iterations, the contact force is actived only, if \(dataCoordinate[0] <= 0\); dataCoordinate is set equal to gap in nonlinear iterations, but not modified in Newton iterations.

Additional information for ObjectContactCircleCable2D:

  • This Object has/provides the following types = Connector
  • Requested Marker type = _None
  • Requested Node type = GenericData

The item ObjectContactCircleCable2D with type = ‘ContactCircleCable2D’ has the following parameters:

  • name [type = String, default = ‘’]:
    connector’s unique name
  • markerNumbers [type = ArrayMarkerIndex, default = [ invalid [-1], invalid [-1] ]]:
    markers define contact gap
  • nodeNumber [type = NodeIndex, default = invalid (-1)]:
    node number of a NodeGenericData for nSegments dataCoordinates (used for active set strategy ==> hold the gap of the last discontinuous iteration and the friction state)
  • numberOfContactSegments [type = Index, default = 3]:
    number of linear contact segments to determine contact; each segment is a line and is associated to a data (history) variable; must be same as in according marker
  • contactStiffness [type = UReal, default = 0.]:
    contact (penalty) stiffness [SI:N/m/(contact segment)]; the stiffness is per contact segment; specific contact forces (per length) \(f_N\) act in contact normal direction only upon penetration
  • contactDamping [type = UReal, default = 0.]:
    contact damping [SI:N/(m s)/(contact segment)]; the damping is per contact segment; acts in contact normal direction only upon penetration
  • circleRadius [type = UReal, default = 0.]:
    radius [SI:m] of contact circle
  • offset [type = Real, default = 0.]:
    offset [SI:m] of contact, e.g. to include thickness of cable element
  • activeConnector [type = Bool, default = True]:
    flag, which determines, if the connector is active; used to deactivate (temporarily) a connector or constraint
  • visualization [type = VObjectContactCircleCable2D]:
    parameters for visualization of item

The item VObjectContactCircleCable2D has the following parameters:

  • show [type = Bool, default = True]:
    set true, if item is shown in visualization and false if it is not shown
  • showContactCircle [type = Bool, default = True]:
    if True and show=True, the underlying contact circle is shown; uses circleTiling*4 for tiling (from VisualizationSettings.general)
  • drawSize [type = float, default = -1.]:
    drawing size = diameter of spring; size == -1.f means that default connector size is used
  • color [type = Float4, default = [-1.,-1.,-1.,-1.]]:
    RGBA connector color; if R==-1, use default color

DESCRIPTION of ObjectContactCircleCable2D

Relevant Examples and TestModels with weblink:

The web version may not be complete. For details, consider also the Exudyn PDF documentation : theDoc.pdf