- Define the load
- Check the model
- Evaluate the margin
- Choose the action
The objective is a defensible decision
A result that misses a requirement is useful when it changes the next engineering action. The team may need to change the load path, revise the geometry, test a material assumption, or correct the model before committing to hardware.
The first task is to distinguish a design limitation from a modeling error. A contour plot alone cannot make that distinction. The checks below describe a general review method; they are not a report of qualification testing on a particular product.
Interrogate the model before the contour
- Confirm geometry, contacts, connections, and omitted features match the decision.
- Trace loads and restraints through a closed free-body argument.
- Check units, material condition, temperature, yield basis, and nonlinear behavior.
- Perform mesh, formulation, and sensitivity checks at governing regions.
- Compare reactions, deformed shape, and first-order calculations with physical expectations.
Separate numerical stress from structural meaning
A local peak may reflect a real notch, a load-introduction effect, a contact edge, or a mathematical singularity. Check whether the reported quantity converges under mesh refinement and whether the chosen failure criterion applies to the material and load case.
For illustration, an allowable of 200 MPa and a comparable applied stress of 250 MPa give utilization 1.25 and reserve margin −0.20. That arithmetic identifies an unmet criterion; it does not identify the cause. A raw strength-to-stress ratio is a different quantity when the allowable already includes a required design factor.
Close the analysis with an action
- Correct or bound suspect inputs.
- Revise geometry, load path, material, connection, or operating limit as appropriate.
- Rerun the controlled model and document sensitivity.
- Define the physical test or code review still required.
- Preserve the below-requirement result as part of the decision record.