Result Types

AutoCalcs provides a comprehensive set of analysis results to help you understand your structure's behavior under load. Results can be viewed visually on the 3D model.

Displacement

Deformation of the structure

Shows how the structure moves from its original position. Displacements include:

  • Translation (Dx, Dy, Dz) - Movement in X, Y, Z directions
  • Rotation (Rx, Ry, Rz) - Rotation about X, Y, Z axes

The visual display shows the deformed shape of the structure, usually magnified so you can see the behavior patterns. The color scale indicates the magnitude of the total displacement.

Reactions

Support forces

Forces and moments that the supports exert on the structure to maintain equilibrium. By Newton's third law, the loads transferred to the foundation are equal in magnitude and opposite in direction.

  • Forces (Fx, Fy, Fz) - Reaction forces in global directions
  • Moments (Mx, My, Mz) - Reaction moments (for fixed supports)

Displayed as arrows at support nodes. Arrow direction indicates force direction.

Axial Force

Member internal force along its axis

The force stretching or compressing a member.

  • Positive (+) - Tension (stretching)
  • Negative (-) - Compression (squashing)

Displayed as a diagram along the member length. Important for designing trusses, columns, and bracing.

Shear Force

Member internal force perpendicular to axis

Forces trying to slice the member.

  • Vy (Major Shear) - Shear force in the local y-direction (typically vertical shear for beams)
  • Vz (Minor Shear) - Shear force in the local z-direction (typically horizontal shear)

Displayed as a filled diagram perpendicular to the member axis.

Bending Moment

Internal bending resistance

The moment causing the member to bend.

  • Mz (Major Moment) - Moment about the local z-axis (typically causing vertical bending). This is the primary moment for floor beams.
  • My (Minor Moment) - Moment about the local y-axis (causing sideways bending).

Displayed as a filled diagram drawn on the tension side of the member.

Torsion

Twisting moment

The internal twisting moment about the member's own longitudinal axis (Mx). It arises wherever load is applied away from the shear centre, on curved or cranked members, or where one end is held against rotation while the rest twists.

This is uniform (St. Venant) torsion, resisted by the section's torsion constant J and shear modulus G. Warping (non-uniform) torsion is not modelled. For open thin-walled sections such as I-beams, channels, angles and tees that are restrained against warping at their ends, two things follow: the true torsional stiffness is higher than J alone, so the reported rotation can be larger than reality, and the warping normal stresses (which often govern torsion in these shapes) are not included in the results. Run a separate torsion check to your design code for such members, and note that the built-in steel design checks cover torsion for closed hollow sections only. Closed sections (hollow tubes and boxes) carry torsion almost entirely through St. Venant shear, so this result applies to them directly.

Units

Results are displayed in your currently selected unit system (Metric or Imperial).

Metric (SI)

  • Displacement - mm or m
  • Force (Axial, Shear, Reactions) - kN
  • Moment (Bending, Torsion) - kN·m

Imperial (US)

  • Displacement - in or ft
  • Force - kip or lbf
  • Moment - kip·ft or lb·ft

You can change unit settings at any time in the Settings dialog.

Result Sign Conventions

Member Internal Forces

Internal forces follow the member's local coordinate system:

  • Axial - Tension is positive
  • Shear - Positive shear acts in positive local y/z direction on a positive face
  • Moment - Positive moment acts counter-clockwise about local axis (Right Hand Rule)

Reactions

Reactions follow the global coordinate system:

  • +Fy - Upward reaction force
  • +Fx - Reaction to the right