organicabaqus建模中映射节点的方法

2021年1月21日发(作者：圆体英文)
Mapping a set of nodes from one coordinate system to another

You
can
map
a
set
of
nodes
from
one
coordinate
system
to
another.
You
can
also
rotate,
translate,
or
scale
the
nodes
in
a
set
by
using
a
more
direct
method instead of coordinate system mapping. These capabilities are
useful
for
many
geometric
situations:
a
mesh
can
be
generated
quite
easily
in a local coordinate
system (for example,
on the surface
of a cylinder)
using
other
methods
and
then
can
be
mapped
into
the
global
(
X
,
Y
,
Z
)
system.
In other cases some parts of your model need to be translated or rotated
along a given axis or scaled with respect to one point.
The mapping capability cannot be used in a model defined in terms of an
assembly of part instances.
The
following
different
mappings
are
provided:
a
simple
scaling;
a
simple
shift and/or rotation; skewed Cartesian; cylindrical; spherical;
toroidal;
and,
in
Abaqus/Standard
only,
blended
quadratic.
The
first
five
of these mappings are shown in
Figure 2.1.1
–
13
.
Figure 2.1.1
–
13
Coordinate systems; angles are in degrees.

Blended quadratic mapping is shown in
Figure 2.1.1
–
14
.
Figure
2.1.1
–
14

Use
of
blended
quadratic
mapping
to
develop
a
solid
mesh
onto a curved block.

In all cases the coordinates of the nodes in the set are assumed to be
defined in the local system: these local coordinates at each node are
replaced with the global Cartesian (
X
,
Y
,
Z
) coordinates defined by the
mapping. All angular coordinates should be given in degrees.
You
can
use
either
coordinates
or
node
numbers
to
define
the
new
coordinate
system,
the
axis
of
rotation
and
translation,
or
the
reference
point
used
for scaling.
The
mapping
capability
can
be
used
several
times
in
succession
on
the
same
nodes, if required.
Scaling the local coordinates before they are mapped
For all mappings except the blended quadratic mapping, you can specify
a scaling factor to be applied to the local coordinates before they are
mapped.
This facility is useful for “stretching” some of the coordinates that
are
given.
For
example,
in
cases
where
the
local
system
uses
some
angular
coordinates
and
some
distance
coordinates
(cylindrical,
spherical,
etc.),
it may be preferable to generate the mesh in a system that uses distance
measures in the angular directions and then scale onto the angular
coordinate system for the mapping.
Two different scaling methods are available.
Specifying the scaling factors directly
A
first
method
of
scaling
the
nodes
with
respect
to
the
origin
of
the
local
system
is
to
specify
the
scale
factors
directly.
In
this
case
the
scaling
is done at the same time as the mapping from one coordinate system to
another.
Input File Usage:

*
NMAP
, NSET=
name

first data line

second data line

scale factor for first local coord, scale
factor for second local coord,
scale factor for third local coord



Specifying the scaling with respect to a reference point
Alternatively,
you
can
scale
with
respect
to
a
point
other
than
the
origin.
The reference point with respect to which the scaling is done can be
defined by using either its coordinates or the user node number.
Input File Usage:

U
se the following option to define the
scaling reference point by using its
coordinates (default):
*NMAP
, TYPE=SCALE, DEFINITION=COORDINATES

X-coordinate of reference point,
Y-coordinate of reference point,
Z-coordinate of reference point

scale factor for first local coord, scale
factor for second local coord,
scale factor for third local coord