Result Diagrams
After running the analysis, CalcSteel displays internal force diagrams directly on the 3D model. Each diagram type reveals different structural behavior — use them to understand how loads flow through your structure.
Switching Between Diagrams
Use the diagram selector in the bottom toolbar to switch between result types. The active diagram is highlighted. You can also cycle through load combinations to see how each one affects the structure.
Diagram Types
MzBending Moment — Major Axis (Mz)
Shows the distribution of bending moment about the strong axis. This is typically the most critical diagram for beam design — peaks indicate where the beam is most stressed in flexure.
Use this to check if beams are properly sized and if moment distribution matches your expectations.
MyBending Moment — Minor Axis (My)
Bending moment about the weak axis. Usually smaller than Mz, but important for biaxial bending checks and lateral loads.
Check this when your structure has loads in both directions or when verifying lateral-torsional buckling.
VzShear Force — Major Axis (Vz)
Vertical shear force diagram. Shows how transverse forces are distributed along each bar. Maximum shear typically occurs near supports.
Verify that shear capacity is adequate, especially at connections and near concentrated loads.
VyShear Force — Minor Axis (Vy)
Shear force in the weak axis direction. Relevant for structures with lateral loads or asymmetric loading.
Check this for frames with wind loads or when bars carry forces in both transverse directions.
NAxial Force (N)
Tension and compression forces along the bar axis. Positive values indicate tension, negative values indicate compression.
Critical for column design and truss analysis. Check for buckling in compressed members.
DeformedDeformed Shape
Shows the amplified deformed shape of the structure under load. The amplification factor is automatic so you can visualize displacements clearly.
Use this to verify that the structure behaves as expected and to check serviceability limits (maximum deflection).
Reading Diagram Values
Hover over any bar to see the exact value at that point. The diagram color scale indicates magnitude — darker colors mean higher values. Positive and negative values are shown on opposite sides of the bar axis.
Sign Convention
CalcSteel uses the standard engineering sign convention: positive axial force (N) means tension, negative means compression. Bending moments follow the right-hand rule relative to the bar local axis. Shear forces are positive in the direction of the positive local axis.
Load Combinations
Each diagram shows results for the currently selected load combination. Use the combination selector to switch between ULS (ultimate), SLS (serviceability), and individual load cases. The envelope option shows the critical values across all combinations.