*PolyBeam()

Creates a polybeam.

Syntax

*PolyBeam(beam_name,"beam_label",pt_1,pt_2,,pt_n)

Arguments

beam_name
The variable name of the polybeam.
Data type: varname
beam_label
The descriptive label of the polybeam.
Data type: label
pt_1, pt_2, ..., pt_n
The points that describe the polybeam
Data type: Point

Example

*Point(pt_1, "Point 1")
*Point(pt_2, "Point 2")
*Point(pt_3, "Point 3")
*Point(pt_4, "Point 4")

*PolyBeam(pb_stabar, "Stab bar", pt_1, pt_2, pt_3, pt_4)

Context

*BeginMdl()

*DefineAnalysis()

*DefineSystem()

Properties

Table 1.
Property Returns Data Type Description
beam@pt_1 Beam The beam on the polybeam originating at pt_1.
body@pt_1 Body The dummy body on the beam at pt_1.
label string The descriptive label of the polybeam.
state boolean Control state (TRUE or FALSE).
varname string The variable name of the polybeam.
Rho real The density of the polybeam.
E real The Young's modulus of elasticity.
G real The shear modulus of elasticity.
OD real The outer diameter of the polybeam cross section.
ID real The inner diameter of the polybeam cross section.
AS real The correction factor for the shear deflection.
CRATIO This argument indicates the structural damping matrix is a ratio of the stiffness matrix.

Comments

A polybeam is modeled as a number of beam segments connecting intermediate bodies created internally by MotionView. The mass and inertia properties of the polybeam are modeled as lumped mass and inertias of intermediate bodies.

The intermediate bodies created for a polybeam can be accessed by specifying one of the point locations used to define the polybeam. For example, the body located at pt_3 in pb_stabar can be accessed as pb_stabar.body@pt_3. Similarly the beam segments of a polybeam may be accessed by specifying the point from where it originates. For example, the beam between pt_2 and pt_3 can be accessed as pb_stabar.beam@pt_2.