FEA Validation of an Asymmetrical Module During SPMT Transport Through UK Infrastructure Constraints

Project context
A highly asymmetrical industrial module required road transport using SPMTs through a constrained UK route including tight radii, camber changes, and controlled bridge crossings.

Although globally robust, the module had:

• Uneven mass distribution

• Slender secondary members

• Connections sensitive to torsional distortion

The transport contractor required confidence that realistic transport load cases would not induce unacceptable local damage.

Why FEA was essential
Standard transport load factors did not capture:

• Torsional distortion during turning manoeuvres

• Differential axle loading effects

• Combined vertical + lateral + torsional actions

Equitus FEA scope

• Derivation of transport load cases reflecting:

  • Braking and acceleration

  • Turning-induced torsion

  • Road camber and surface irregularities

• Global–local FEA approach:

  • Global distortion of the module frame

  • Local stress assessment at critical welds and attachments

• Sensitivity studies to quantify tolerance to route deviations

Outcome

• Demonstrated that global behaviour was acceptable

• Identified local overstress at discrete welded joints during turning events

• Allowed pre-emptive reinforcement of only the governing details

• Avoided conservative transport restrictions or redesign