Abdel-Karim-Ohno模型改进及Z2CDN18.12N不锈钢棘轮效应预测.

In order to better describe the uniaxial ratcheting behavior of Z2CDN18.12N austenitic stainless steel, the Abdel-Karim-Ohno model was improved under the framework of the unified viscoplastic cyclic constitutive theory. By introducing a plastic strain memory surface into the isotropic hardening rule, the model parameters were determined. Further, the Abdel-Karim-Ohno model and the improved Abdel-Karim-Ohno model were used to predict the uniaxial ratcheting effect behavior of Z2CDN18.12N austenitic stainless steel at the room temperature. The influences of mean stress, stress amplitude, stress rate and loading history on the uniaxial ratcheting strain of Z2CDN18.12N austenitic stainless steel were studied by the two models, respectively. The uniaxial ratcheting strain level increased with the increasing mean stress and stress amplitude, decreased with the increasing stress rate, being more sensitive to the lower stress rate, and the loading history had great influence on the ratcheting behavior. Comparison of the prediction results of the two models with the experimental data proved the effectiveness of the improved model. [ABSTRACT FROM AUTHOR]