Structural designs with consideration of both material and structural failures

This paper provides a simplified formula for modeling the transition between material and structural failures in static and dynamic loading situations. For static situations, the transition equation allows for the calculation of the ultimate capacity between buckling structural failure and compression material failure modes. For dynamic situations, the transition equation allows for the calculation of a smoothed S-N curve between the constant amplitude fatigue limit, namely, the endurance limit, and the low-cycle, high-stress fatigue limit. The simplified formula is based on a quadratic solution that is curve fit to each failure mode and is verified with existing experimental data.