ObjectANCFBeam

OBJECT UNDER CONSTRUCTION: A 3D beam finite element based on the absolute nodal coordinate formulation, using two 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; assuming dimensions \(w_y\) and \(w_z\) in cross section, the local position range is \(\in [[-L/2,L/2],\, [-wy/2,wy/2],\, [-wz/2,wz/2] ]\).

Additional information for ObjectANCFBeam:

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

The item ObjectANCFBeam with type = ‘ANCFBeam’ 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.
• crossSectionPenaltyFactor [\(f_{cs} = [f_{yy},\,f_{zz},\,f_{yz}]\tp\), type = Vector3D, default = [1.,1.,1.]]:

  [SI:1] additional penalty factors for cross section deformation, which are in total \(k_{cs} = [f_{yy}\cdot k_{yy},\, f_{zz}\cdot k_{zz},\, f_{yz}\cdot k_{yz}]\tp\)
• visualization [type = VObjectANCFBeam]:

  parameters for visualization of item

The item VObjectANCFBeam 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

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DESCRIPTION of ObjectANCFBeam

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

• Position:

  global position vector of local position vector
• Displacement:

  global displacement vector of local position vector
• Velocity:

  global velocity vector of local position vector
• VelocityLocal:

  global velocity vector of local position vector
• AngularVelocity:

  global angular velocity vector of local (axis) position vector
• AngularVelocityLocal:

  local angular velocity vector of local (axis) position vector
• Acceleration:

  global acceleration vector of local position vector
• Rotation:

  3D Tait-Bryan rotation components of cross section rotation
• RotationMatrix:

  rotation matrix of cross section rotation as 9D vector

Detailed description coming later.

Relevant Examples and TestModels with weblink:

ANCFBeamEigTest.py (TestModels/), ANCFBeamTest.py (TestModels/), geometricallyExactBeamTest.py (TestModels/), rightAngleFrame.py (TestModels/)

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