多晶镍基合金循环塑性细观本构关系

基于晶体塑性的本构理论,考虑金属材料晶体细观塑性变形流动的各向异性性质及晶体滑移的非线性运动硬化,以Voronoi多晶集合体作为材料的代表性体积单元(RVE),用晶体塑性模拟描述ZSGH4169多晶镍基合金材料的细观本构关系,对ZSGH4169多晶镍基合金进行了晶粒尺度的对称和非对称循环细观分析.通过对称循环数值模拟表明:该模型适合模拟金属材料循环试验中常见的应变硬化现象和Bauschinger效应;通过非对称循环数值模拟表明该模型具有对棘轮效应的描述能力,计算中发现背应力的演化对滑移切应变率有很大的影响,滑移切应变率的数值很大程度取决于背应力演化主导的非线性硬化过程.

Mesoscopic mechanical constitutive relation of cyclic plasticity for nickel based polycrystalline superalloy

Based on the constitutive relation in crystal plasticity,anisotropy of cyclic hardening of meso-plastic deformation flow and nonlinear movement of crystal slip was considered.Using the Voronoi polycrystalline as a representative volume element (RVE),the mesoscopic mechanical constitutive relation of nickel based polycrystalline superalloy was described by the theory of crystal plasticity.Calculations of both symmetric and asymmetric cycle analyses were conducted.The results of symmetric cyclic analyses indicate that the model is suitable to simulate the strain hardening phenomenon and Bauschinger effect.The results of asymmetric cycle analyses show that the model has the ability to describe ratchet behavior,back stress calculations have great impact on the evolution of slip shear strain rate,slip shear strain rate value largely depends on nonlinear evolution led by back stress hardening process.