1. initial modeling 1. start with a free body diagram 2. estimate results with hand calcs and double check units at all steps 3. obtain material properties from a reliable source 4. tabulate loads, temperatures, accelerations, and number of cycles 5. evaluate design at worst case load and thermal conditions 2. check inputs and assumptions 1. sanity check material cards across full range of temperatures 2. use principal stress for brittle materials (e.g. elongation < 3%) 3. consider environmental corrosion (e.g. saltwater, galvanic cells) 4. include relevant thermal, weld, and casting knockdown factors 5. ensure sliding parts are resistant to galling 6. Ensure fatigue calculations are corrected for temperature and include vibration with amplification factor appropriate for the loading frequencies 7. Assess creep for sustained loads at high temperatures 8. Appropriate factor of safety accounting for whether personnel are present 3. simulation 1. perform mesh convergence study 2. sanity check modal analysis with hand calcs and intuition 3. ensure engineering vs true stress/strain and nlgeom are used properly 4. ensure fillets are large enough to low cycle fatigue and the mesh adequately captures the stress concentration (e.g. 3 elements across the radii) 5. exaggerate deformations in FEA to check contacts 6. Account for worst case tolerances and fit-up loads (actual vs CAD) 4. final checks 1. Assess margin of safety on yield, ultimate, elongation, stability, fatigue, and joint gapping 2. Verify results with hand calcs (SumForces=0, thermal strain, stress) 3. Correlate with test data and get peer review 4. Document results, inputs, and assumptions