Ratcheting characterization and its effect on low cycle fatigue behavior of DP600 steel sheet under cyclic shear path

• Published in: International journal of fatigue Vol. 166; p. 107231
• Main Authors: Zhang, Z.R., Yue, Z.M., Bao, Y.M., Gao, J.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01-01-2023
• Subjects: Cyclic shear path; Dual-phase steel; Heterogeneous material; Low cycle fatigue; Ratcheting; Dual-phase steel; Heterogeneous material; Ratcheting; Cyclic shear path; Low cycle fatigue
• ISSN: 0142-1123; 1879-3452
• DOI: 10.1016/j.ijfatigue.2022.107231

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•The ratcheting effect of DP600 steel sheet under the shear path is studied.•The history of ratcheting loading can cause grain refinement behaviors during fatigue loading.•The ratcheting strain before obvious damage is beneficial to prolong the fatigue life.•The stress less than the yield point is a necessary condition for ratcheting inhibition.
For thin-walled metal parts, the effects of shear deformation must be considered. In this study, a device for cyclic shear tests was designed, and a DP600 sheet was used to study the fatigue behavior under a shear path without buckling. Ultimately, based on the results, the ratchet behavior, effect of ratchet deformation on fatigue, and law of ratchet inhibition were analyzed and discussed. The local strain concentration and high dislocation density caused by ratcheting loading led to local grain refinement during strain-controlled fatigue loading, improving the cyclic strength and fatigue life.