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PROPERTY PHYSICAL BOX [phname] real1 ... realn
PROPERTY PHYSICAL BOX phname OFFSET off1 off2
PROPERTY PHYSICAL BOX phname ORIENTATE zdir

      

This command is used to define or redefine beam sectional properties for a box section beam. The different FEMGEN translators will calculate areas, moments of inertia etc. as needed by the supported FE programs.


phname = name of new physical property to be defined or name of existing
physical property to be modified. If no name is given a new name
will be automatically generated.
reals = H B to define a solid section. See the diagram below.
H B TH to define a box-section tube where TB=TH.
H B TH TB to define a box-section tube.
off1 = off1 is used to define the local offset at the start of the beam using
either a point name or an offset vector (x,y,z). When a point name is
used the offset will be the vector from the start of the first beam
element to the point.
off2 = off2 is used to define the local offset at the end of the beam using
either a point name or an offset vector (x,y,z). When a point name is
used the offset will be the vector from the end of the last beam
element to the point.
zdir = zdir is used to define the beam local z' axis direction; this can be
done either with an orientation vector or a point name. The orientation
vector requires three components to define the beam local z' axis in
terms of the global axis system (the default local direction is 0,0,1).
When a point name is used the beam local z' axis is defined
orthogonal to the line to which the property is attached and in a
direction towards the point. See example 3 below.

To assign physical properties to a certain part of the structure use the PROPERTY ATTACH command.


 
Figure 2.117: Box cross section
\begin{figure}
\centerline{
\psfig {figure=diagrams/beam_box.ps,height=1.75in}
}\end{figure}

Examples:

1.
PROPERTY PHYSICAL BOX PH1 1.5 1.5

Define a box section beam called PH1 of solid section where H=1.5 and B = 1.5.

2.
PROPERTY PHYSICAL BOX PH1 OFFSET 0 0 1 0 0 1

Define a beam offset for a box section beam called PH1 with two identical unit offsets in the z-direction.

3.
PROPERTY PHYSICAL SECT1 ORIENTATE -1 0 0
PROPERTY PHYSICAL ORIENTATE SECT2 P9

The first command defines the beam local z' axis using an orientation vector and the second uses a point to define the beam local z' axis direction. In the figure below the property SECT1 has been attached to the left hand line and the property SECT2 has been attached to the right hand line. The local axis system for the lines is shown with LABEL GEOMETRY AXES.


 
Figure 2.118: Beam local axis systems
\begin{figure}
\centerline{
\psfig {figure=diagrams/ori.eps,height=2in}
}\end{figure}

See also the following commands

'LABEL GEOMETRY AXES'
'LABEL GEOMETRY PHYSICAL'
'LABEL MESH PHYSICAL'
'PROPERTY ATTACH'
'UTILITY DELETE PHYSICAL'
'UTILITY TABULATE GEOMETRY PHYSICAL'


next up previous contents index
Next: PROPERTY PHYSICAL DEFINE Type_name Nvals [ORIENT] Up: PROPERTY PHYSICAL Previous: PROPERTY PHYSICAL

Femsys Limited
1st October 1999