<p>The present study intends to evaluate the local ratcheting of a high-strength steel alloy with a dual-phase (DP) structure at which both strength and ductility are balanced. The notch root ratcheting of as-received and pre-strained dual-phase 590 (DP590) samples has been evaluated over the asymmetric loading cycles through the use of two hardening rules developed earlier by Ahmadzadeh-Varvani (A-V) and Chaboche (CH). The cyclic stresses at the notch root were computed by the Neuber rule and were then taken as inputs to generate the progressive stress–strain hysteresis loops at the notch root of DP590 steel samples. The unidirectionally and bidirectionally pre-strained notched samples possessed greater resistance against ratcheting as compared with the as-received samples. The local ratcheting values predicted by the A-V and CH hardening rules consistently showed overestimation and underestimation responses in the as-received and pre-strained samples as compared with those of experimental data.</p> Graphical abstract <p></p>

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Local ratcheting evaluation of pre-strained notched high-strength steel samples subjected to asymmetric loading cycles

  • F. Hatami,
  • A. Varvani-Farahani

摘要

The present study intends to evaluate the local ratcheting of a high-strength steel alloy with a dual-phase (DP) structure at which both strength and ductility are balanced. The notch root ratcheting of as-received and pre-strained dual-phase 590 (DP590) samples has been evaluated over the asymmetric loading cycles through the use of two hardening rules developed earlier by Ahmadzadeh-Varvani (A-V) and Chaboche (CH). The cyclic stresses at the notch root were computed by the Neuber rule and were then taken as inputs to generate the progressive stress–strain hysteresis loops at the notch root of DP590 steel samples. The unidirectionally and bidirectionally pre-strained notched samples possessed greater resistance against ratcheting as compared with the as-received samples. The local ratcheting values predicted by the A-V and CH hardening rules consistently showed overestimation and underestimation responses in the as-received and pre-strained samples as compared with those of experimental data.

Graphical abstract