September 4, 2025
|
Featured,
RISA-3D,
RISAFloor,
RISAFoundation
RISA
software
products
use
different
sign
conventions
depending
on
the
product’s
purpose
and
typical
use
case.
While
the
conventions
are
logical
within
each
program,
they
may
appear
inconsistent
when
moving
between
tools
like
RISA-3D,
RISAFloor,
RISAFoundation,
and
RISAConnection.
This
article
consolidates
the
sign
convention
rules
for
common
forces
and
moments
across
these
programs,
so
users
have
a
single
reference
point
for
interpretation.
Overview
Table
of
Sign
Conventions
Program
Positive
Moment
(M)
Shear
(V)
Direction
Axial
(P)
Direction
Display
Notes
RISA-3D
Top
fiber
in
tension
(sagging)
→
Negative
Bottom
fiber
in
tension
(hogging)
→
Positive
Downward
on
right
face
=
Positive
Tension
=
Negative
Global/local
directions
shown
in
results
grids
RISAFloor
Top
fiber
in
tension
(sagging)
→
Positive
Bottom
fiber
in
tension
(hogging)
→
Negative
Downward
on
right
face
=
Positive
Tension
=
Positive
Matches
common
AISC/textbook
convention
RISAFoundation
Top
fiber
in
tension
(sagging)
→
Positive
Follows
structural
sign
convention
Tension
=
Positive
Matches
RISAFloor
convention
RISAConnection
Based
on
free
body
diagram
convention
(force
direction
matters,
not
internal
sign)
Force
arrows
into
member
=
Compression
Force
arrows
away
=
Tension
Force
direction
shows
magnitude/type
Blue
arrows
clarify
direction
of
loads
⚠️
Important:
The
“top
fiber”
is
always
the
side
of
the…