While members (beams and columns) follow conventions tied to their local axes, interpreting results for wall panels, plate elements, and design strips requires a slightly different perspective. These elements deal with both in-plane and out-of-plane behavior, and the sign conventions can change depending on the program and axis orientation.
| Element Type | Positive Moment (M) | Shear (V) | Axial (P) | Notes |
|---|---|---|---|---|
| Wall Panels – In-Plane | Compression in positive local-y face | Downward on right face | Tension = Positive | Applies to in-plane forces only |
| Wall Panels – Out-of-Plane | Compression on positive local-y face | N/A | N/A | Defines “positive bending” convention |
| Plates (RISA-3D) | Positive Mx or My = Top surface in tension | Shear follows right-hand rule | Tension = Positive | Local Z-axis defaults upward |
| Plates (RISAFoundation) | Positive Mz = Top surface in compression | Shear follows right-hand rule | Tension = Positive | Local Z-axis defaults downward |
| Design Strips / Support Lines | Sagging = Positive (bottom fiber in tension) | Downward on right face | Tension = Positive | Matches slab design workflows |
Wall panels report forces in both in-plane and out-of-plane directions.
In-plane:
Axial = Positive tension
Shear = Positive when downward on the right face
Out-of-plane:
Positive bending = compression on the positive local-y face of the wall
This convention ensures consistency whether the panel is resisting gravity or lateral loads.
The most common source of confusion is how RISA programs define the local Z-axis of plates.
In RISA-3D:
Positive local-Z points upward by default.
The “top fiber” referenced in the Help File corresponds to the positive-local-z side, which in this case is physically the top.
In RISAFoundation:
Submeshed plates are oriented with their positive local-Z pointing downward.
The “top fiber” is still the positive-local-z side, but this means results may look opposite compared to RISA-3D.
💡 Key Clarification: When the Help File refers to the “top fiber,” it always means the fiber on the positive-local-z-axis side of the plate—not necessarily the physical top surface of the slab.
This explains why moment results may appear inverted between RISA-3D and RISAFoundation, even though the physical interpretation (top surface in compression) remains consistent.
For slabs and mats, design strips (FD and FL diagrams) simplify plate results into familiar design line outputs.
Positive moment = sagging (bottom fiber in tension)
Shear = downward on right face positive
Axial = tension positive
These results are intended to match conventional reinforced concrete design workflows.
Each RISA program is optimized for a specific stage of design:
RISAFloor and RISAFoundation cater to design engineers referencing structural code conventions.
RISA-3D reflects analytical principles that simplify complex 3D modeling.
RISAConnection visualizes external forces at connections, similar to detailing or fabrication shop drawings.
Understanding this context helps reconcile results across the programs.
Looking instead for Sign Conventions for Members in RISA? Read More
Check out our Help File for more info on sign convention in the corresponding products by clicking the links below.
RISA-3D Sign Convention
RISAFloor Sign Convention
RISAFoundation Sign Convention