为探求形式简洁,参数较少,便于工程应用的循环本构模型,本文基于边界面模型和多面模型理论,建立了一个可描述金属材料三轴循环加载力学行为的三面本构模型.把塑性应变分解成塑性应变1和塑性应变2,塑性应变1对应于一套屈服面-边界面模型,塑性应变2对应于一套单屈服面模型.提出了当前应力点与边界面上对偶点之间距离的演变公式,基于一致性条件得出边界面模型中塑性模量的计算与运动硬化准则的联系.采用塑性应变作为硬化参数,应用关联流动法则计算塑性应变.相比于经典的边界面模型,本文模型形式简明;相比于前人修正随动硬化准则模型,本文模型需要的材料参数较少.结合金属稳定材料U71Mn的单轴循环实验结果,对其4种力学行为进行模拟,分析了非对称应力循环下平均应力和应力幅值对稳定材料棘轮效应的影响,以及对称应变循环下材料的最大应变幅值记忆效应.研究结果表明,本文模型的模拟结果与前人文献的实验结果一致性较好,可为研究材料的本构行为提供一条新的途径.%Based on the theories of bounding surface and multiple surface, a three-surface cyclic constitutive model, which is applicable for engineering because of the simple form and less parameters, was established to describe metal material behavior under the triaxial cyclic loadings.The plastic strain was decomposed into plastic strain 1 corresponding to a bounding surface model and plastic strain 2 corresponding to a single yield surface model.An evolution formula of the distance between the current stress and the image stress on the bounding surface was developed, which makes the plastic modulus calculation be coupled with the kinematic hardening rule through the consistency condition of the yield surface.As the hardening parameter, the plastic strain was calculated according to the associated flow rule.Compared with the classic bounding surface models, it has a concise form, and compared with the modified kinematic hardening rule models, it has less parameters.The existing experimental results about stable metal material U71Mn under uniaxial cyclic loading were adopted, and four mechanical behaviors were considered.The ratcheting were simulated by the model considering the effect of mean stress and stress amplitude under asymmetrical stress cycling, and the maximum strain amplitude memory effect was analyzed under symmetrical strain cycling.The calculated results agree well with the experimental results, which means the proposed model provides a new method to study the constitutive relation.
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