May 26, 2020
|
Time History,
RISA-3D,
New
RISA-3D
can
be
used
to
model
the
effects
of
rotating
machinery
on
their
support
structures.
In
the
model
below,
we
have
a
structure
which
is
to
support
a
piece
of
rotating
machinery.
To
begin,
we
will
add
the
load
at
each
node
where
the
machinery
will
bear
on
the
support
beams.
We
have
done
this
by
using
the
Nodal
Loads
tool
and
changing
the
type
to
Load.
In
our
example,
1000
lbs
at
four
locations.
Once
the
load
is
added,
we
need
to
simulate
a
rotation
caused
by
the
machinery
at
these
four
points.
To
accomplish
this,
a
Time
History
function
can
be
created
that
will
simulate
the
operation
frequency
of
our
machinery.
To
do
this,
navigate
to
Advanced
>
Time
History
>
Generate,
where
the
frequency
that
will
occur
at
each
bearing
point
can
be
input.
As
shown
below,
we
can
modify
the
Time
History
function
in
order
to
simulate
the
start
up
and
shut
down
of
the
machinery.
For
additional
information
on
the
Ramp
Up
and
Coast
Down
sections
of
the
time
history
function,
check
out
the
support
article
listed
below:
With
the
function
created,
the
time
history
load
is
applied
by
opening
the
Time
History
Loads
spreadsheet,…
