...
How
...
do
...
I
...
retrieve
...
the
...
seismic
...
forces
...
which
...
are
...
in-plane
...
to
...
semi-rigid
...
diaphragms?
...
ANSWER:
...
To
...
retrieve
...
membrane
...
forces
...
which
...
occur
...
in-plane
...
to
...
semi-rigid
...
diaphragms
...
when
...
user-defined
...
seismic
...
loads
...
are
...
applied
...
to
...
a
...
structure,
...
loads
...
should
...
be
...
directly
...
applied
...
either
...
to
...
floors
...
as
...
distributed
...
loads,
...
or
...
at
...
discrete
...
points
...
according
...
to
...
seismic
...
...
distribution.
...
User-defined
...
seismic
...
loads
...
should
...
not
...
be
...
applied
...
to
...
a
...
semi-rigid
...
diaphragm
...
because
...
the
...
software
...
will
...
then
...
concentrate
...
and
...
apply
...
seismic
...
load
...
as
...
a
...
point
...
load
...
only
...
at
...
the
...
center
...
of
...
mass.
...
| Info |
|---|
NOTE: *This summary also applies to user-defined wind loads. {info} {hidden-content} *Related Incident:* * {incident:no=47379|comment=Tech Support Question - ETABS 9.7.4} {hidden-content} |