| Abstract [eng] |
This paper provides experimental and analytical evaluation of durability of nonhardened and hardened by EMT specimens of grade 45 steel with stress concentrators, under low cycle pure bending. For this type of loading modes was carried out durability analysis, taking into account fatigue and quasi-static damage depending on loading level and number of semicycles. Stress and strain concentration coefficients were calculated by analytical and finite element methods (FEM) under elastic plastic cyclic loading. It was determined, that in specimens with the stress concentrators under low cycle pure bending, hardened surface has nonsignificant influence on durability. Performed analytical investigation showed, that suggested method for quasi-static and fatigue damage summation, when accumulated plastic strain and the width of the hysteresis loop are taken into account, provides a very good agreement with the experimental results at stress concentration zones of surface-hardened parts under pure bending. |
