Deformations
How to read and validate displacement results in Dr.Q.
If you only have 2 minutes
Check that the deformation direction is physically correct and that the magnitude is in a realistic order of magnitude.
What Dr.Q shows
The displacement result shows how far each point in the model moves from its undeformed position. Dr.Q displays:
- Total displacement — magnitude of the displacement vector
- Directional (X, Y, Z) — displacement component along each axis
- Deformed shape — geometry scaled up for visibility (check the actual maximum value in the legend, not the visual)
Checking direction
Does the part move where and how you'd expect it to?
- A cantilever beam loaded at the tip should deflect at the tip
- A plate under uniform pressure should bulge outward at the centre
- A shaft in torsion should rotate at the free end
If the deformation goes in an unexpected direction, the load direction or boundary condition placement is wrong.
Checking magnitude
Compare the result to a quick hand calculation or engineering intuition:
- Steel bracket with a 1000 N load: deformation in the tenths-of-a-millimetre range is typical
- Large aluminium structure: deformation in the millimetre range under service loads
- If you get metres of deformation on a steel part, check material units (GPa vs MPa)
NaN or Inf in the displacement result means the solver found a singular system. The model is underconstrained — a body is free to move as a rigid body. Add the missing boundary condition.
Scale factor
The displayed deformation is exaggerated for visibility. The actual maximum displacement is the number shown in the legend — always use that value for engineering assessment, not the visual scale.