Spoon HitchStructural Redesign
A focused geometry redesign reduced the reported peak stress under the OEM’s specified static load case while retaining the hitch interfaces and material specification.
Comparison basis
- Loading
- The same specified static load case before and after redesign.
- Material
- The original material grade and heat treatment specification retained.
- Interfaces
- Mounting, hitch engagement and surrounding clearance treated as fixed constraints.
Resolve the stress concentration
The initial spoon hitch analysis placed the local peak close to the material yield reference used for the assessment. The OEM had already identified the problem; Fabrixon’s brief was to resolve it within the existing interface envelope.
Reanalysis in ANSYS Mechanical focused on a sharp internal transition where the load passed through a locally restricted section. Progressive mesh refinement was used to check the reported peak before the geometry was changed.
- Root cause
- The concentration occurred at an abrupt change in the load carrying geometry.
- Constraint
- The engagement geometry, mounting pattern and surrounding envelope could not be treated as free redesign space.
- Method
- Local geometry iteration with repeat analysis, rather than a changed load case or a material upgrade.
Change the load path, not the brief
The redesign combined smoother transitions and local support while retaining the OEM’s fixed interfaces. Each iteration was reanalysed with the same mesh refinement discipline used for the baseline.
- 01
Smooth the transition
Replace the sharp internal change with fillet geometry that distributes load through the transition.
- 02
Support the peak region
Add supporting section where the analysis showed the demand, rather than increasing material uniformly across the component.
- 03
Recheck the envelope
Balance the stress improvement with clearances, mounting constraints and manufacturability in each iteration.
Lower stress under the same load
Repeat analysis confirmed a reduction in peak von Mises stress from the initial to the redesigned geometry. The improvement was achieved through geometry while the stated material and load case remained unchanged.
| Metric | Initial geometry | Redesigned geometry |
|---|---|---|
| Peak von Mises stress | 648 MPa | 338 MPa |
| Peak stress reduction | Baseline | 48% lower |
The stress reduction is rounded to the nearest whole percentage. This comparison is a static structural result, not a fatigue life prediction.
Evidence for the redesigned release
The engineering engagement combined the initial analysis, geometric redesign and repeat assessment in one report. The revised component was released for fabrication without changing the mounting or hitch engagement geometry.
- Design change
- Smoother transitions and targeted local section support addressed the source of the concentration.
- Analysis scope
- Static linear FEA under the specified load case. Fatigue under service load history remains a separate assessment.
- Release evidence
- The engineering report documented the comparison, modelling basis and scope for the OEM’s design release.