February 15, 2022
|
RISA-3D,
New,
Analysis,
P-Delta
RISA-3D
continues
to
be
at
the
cutting-edge
of
finite
elements
analysis
software
with
the
release
of
the
Geometric
Nonlinear
Stiffness
method
for
use
during
P-Delta
analysis.
Traditionally,
RISA-3D
considered
P-Delta
effects
using
a
Standard
Nodal
Shear
methodology
which
applies
pseudo
shear
loads
at
the
individual
member
nodes
based
on
the
axial
load,
lateral
deflection
and
member
geometry.
To
select
this
method,
navigate
to
Model
Settings
>
Advanced.
When
comparing
the
two
methods,
the
standard
Nodal
Shear
Method
has
been
used
for
many
years
when
considering
P-Delta
effects
in
RISA-3D.
It
is
a
widely
utilized
methodology
in
evaluating
the
secondary
effect
of
the
structure
and
proved
to
have
great
performance
in
most
cases.
However,
due
to
the
limitations
of
the
method
itself,
it
diverges
quickly
when
axial
loads
approach
the
buckling
loads.
As
a
result,
the
P-Delta
divergence
could
potentially
occur
prematurely
for
some
structures.
Another
limitation
of
this
method
is
that
the
loading
is
node
based,
and
due
to
this,
users
would
have
to
manually
add
internal
nodes
along
the
member
to
properly
consider
the
P-small
delta
effect.
For
additional
information
on
the
Nodal
Shear
Method
in
RISA-3D
and
how
it
handles
small
P-Delta
effects,
visit
our
Online
Help.
Finally,…
