ObjectBeamGeometricallyExact

OBJECT UNDER CONSTRUCTION: A 3D geometrically exact beam finite element, currently using two 3D rigid body nodes. The localPosition \(x\) of the beam ranges from \(-L/2\) (at node 0) to \(L/2\) (at node 1). The axial coordinate is \(x\) (first coordinate) and the cross section is spanned by local \(y\)/\(z\) axes.

Additional information for ObjectBeamGeometricallyExact:

  • This Object has/provides the following types = Body, MultiNoded
  • Requested Node type = Position + Orientation
  • Short name for Python = Beam3D
  • Short name for Python visualization object = VBeam3D

The item ObjectBeamGeometricallyExact with type = ‘BeamGeometricallyExact’ has the following parameters:

  • name [type = String, default = ‘’]:
    objects’s unique name
  • nodeNumbers [type = NodeIndex2, default = [invalid [-1], invalid [-1]]]:
    two node numbers for beam element
  • physicsLength [\(L\), type = PReal, default = 0.]:
    [SI:m] reference length of beam; such that the total volume (e.g. for volume load) gives \(\rho A L\); must be positive
  • sectionData [type = BeamSection, default = BeamSection()]:
    data as given by exudyn.BeamSection(), defining inertial, stiffness and damping parameters of beam section.
  • visualization [type = VObjectBeamGeometricallyExact]:
    parameters for visualization of item

The item VObjectBeamGeometricallyExact has the following parameters:

  • show [type = Bool, default = True]:
    set true, if item is shown in visualization and false if it is not shown; geometry is defined by sectionGeometry
  • sectionGeometry [type = BeamSectionGeometry, default = BeamSectionGeometry()]:
    defines cross section shape used for visualization and contact
  • color [type = Float4, default = [-1.,-1.,-1.,-1.]]:
    RGBA color of the object; if R==-1, use default color

DESCRIPTION of ObjectBeamGeometricallyExact

The following output variables are available as OutputVariableType in sensors, Get…Output() and other functions:

  • Position:
    global position vector of local axis (1) and cross section (2) position
  • Displacement:
    global displacement vector of local axis (1) and cross section (2) position
  • Velocity:
    global velocity vector of local axis (1) and cross section (2) position
  • Rotation:
    3D Tait-Bryan rotation components, containing rotation around \(z\)-axis only
  • StrainLocal:
    6 strain components, containing only axial (\(xx\)) and shear strain (\(xy\))
  • CurvatureLocal:
    3D vector of curvature, containing only curvature w.r.t. \(z\)-axis

Detailed description coming later.

Relevant Examples and TestModels with weblink:

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