考虑材料应变硬化和包辛格效应的厚壁筒自增强理论模型

提出了一种以材料的实际拉-压应力应变曲线为基础，考虑材料应变硬化行为和包辛格效应的厚壁管自增强理论模型．本模型通过直接对实际材料拉-压应力应变曲线进行四段拟合得到所需参数，因此能更好地反映材料的应力-应变特性，给出更精确的残余应力计算结果．模型预测的残余应力和实验测试结果与其他3种自增强理论模型预测结果进行了比较，结果表明，该模型的预测结果和实验测试值吻合，比其他理论模型给出了更精确残余应力预测结果．讨论了包辛格效应和屈服准则对筒壁残余应力的影响．理想弹塑性模型、线性强化模型以及幂硬化模型等都是本模型的特例．

A New Autofrettage Model of Thick-Walled Cylinder Considering the Strain-Hardening and Bauschinger Effect of Material

An autofrettage model considering the material strain-hardening relationship and the Bauschinger effect was proposed based on the actual tensile-compressive stress-strain curve of material and modified yield criterion. The relative parameters are determined by directly fitting the stress-strain curve of material using four equations. The predicted residual stress of autofrettaged tubes from the proposed model was compared with the experimental data and the predictions of other autofrettage models, it shows that the model has stronger curve fitting ability and gives more accurate prediction. The effect of Bauschinger effect and yield criterion on residual stress was discussed. Each of those models such as elastic-perfectly plastic model, linear strain-hardening model, power strain-hardening model, and the combination of those strain-hardening models are all special cases of the proposed model.