It’s not just stress that produces instability
In the Inventor Simulation Suite and Inventor Professional, the FEA solver can determine if a design will fail due to a high stress in the model, but this might only be half the story. If the model is in compression and is a thin or elongated structure, the model could fail due to its structural instability (Buckling) rather than deformation due to high stress. The Autodesk Algor solution includes critical buckling analysis to ensure this won’t be the primary mode of failure.
Thin walled plastic parts or sheet metal could be susceptible to buckling as well as traditional problems like truss or structural frame design.
While the structure below might have a high safety factor of 30 or more for the stress analysis, the buckling analysis shows only a multiplier of 27. This indicates that the structure could fail due to buckling rather than only exceeding the yield point of the material.
Contributed by Ben of the Tata Technologies CAD Geeks