Nonlinear Buckling Design Review Checklist
Review prompts for nonlinear collapse analysis — imperfection, material nonlinearity, load stepping and limit-point interpretation.
Purpose
For checking a nonlinear collapse (buckling) analysis.
Setup
- Is an initial imperfection applied in the shape of the critical buckling mode? — Without imperfection, the model may bifurcate at the eigenvalue
- Is the imperfection magnitude justified — not arbitrary? — Typically based on manufacturing tolerance or t/100
- Is geometric nonlinearity activated? — Large displacement
- Is material nonlinearity included if stresses may exceed yield before collapse? — Plasticity can reduce collapse load
- Is the load stepping fine enough to capture the limit point? — Automatic stepping with minimum increment control
Results
- Is the collapse load identified as a limit point on the load-displacement curve? — Not just the last converged increment
- Is the post-buckling behaviour understood — snap-through or stable post-buckling? — Affects structural safety
- Is the collapse load compared with the eigenvalue prediction? — Ratio indicates imperfection sensitivity
- Is the analysis converged — no spurious termination? — Check message file