Low-cycle bending fatigue of steel bars under random excitation. Part II: Design considerations

In this paper, the low-cycle bending-fatigue strength of square and rectangular steel bars under random loading histories is quantified through an experimental program. Based on the experimental data, and considering the fatigue failure mechanisms, a damage accumulation index formula is established. This formula serves as a foundation for further investigation on structural members with other geometrical shapes, with local buckling effects, and/or with welding residual stress effects, etc. After these effects are considered, design principles for low-cycle bending-fatigue strength of steel members can be developed for earthquake engineering applications.