基于位错密度的晶体塑性有限元方法的数值模拟及参数标定

发布时间：2018-03-21 18:38

本文选题：晶体塑性　切入点：有限单元法　出处：《材料导报》2016年08期 　论文类型：期刊论文

【摘要】：运用ABAQUS有限元分析软件对基于位错密度的晶体塑性有限元方法(CPFEM)及其晶体塑性参数进行了深入的研究。结果表明,CPFEM晶体塑性本构可以准确地体现材料的力学性能。通过讨论不同晶体塑性参数,得到各个参数可以分别控制材料的屈服强度、硬化过程、剪切应变速率、极限强度等性能。此外,为了标定材料的晶体塑性参数引入多晶的代表体积单元(RVE)模型,并讨论了晶粒数以及晶粒规整度对于RVE模型的影响。结果表明,RVE模型的晶粒数达到临界值750个时能够体现等轴晶的宏观各向同性。结合晶体塑性RVE模拟和拉伸试验结果,对Inconel 718合金的晶体塑性参数进行标定,晶体塑性有限元的模拟结果和实验结果的误差小于5%。证明经过标定的晶体塑性参数可以准确反映Inconel 718的力学性能,也使得进一步研究该合金介观晶粒尺度的力学性能成为可能。
[Abstract]:The crystal plastic finite element method (CPFEMM) based on dislocation density and its crystal plastic parameters are studied by using ABAQUS software. The results show that the plastic constitutive model of the crystal can accurately reflect the mechanical properties of the material. By discussing different crystal plasticity parameters, It is obtained that the yield strength, hardening process, shear strain rate, ultimate strength and other properties of the material can be controlled by each parameter. In addition, in order to calibrate the crystal plastic parameters of the material, the representative volume unit (RVE) model of polycrystalline is introduced. The effect of grain number and grain regularity on RVE model is discussed. The results show that the macroscopic isotropy of equiaxed crystal can be reflected when the grain number reaches 750 critical values. The results of plastic RVE simulation and tensile test are combined. The crystal plastic parameters of Inconel 718 alloy are calibrated. The error of the finite element method of crystal plasticity is less than 5. It is proved that the calibrated crystal plastic parameters can accurately reflect the mechanical properties of Inconel 718. It is also possible to further study the mechanical properties of the alloy at mesoscopic grain size.
【作者单位】：上海交通大学材料科学与工程学院;
【基金】：国家自然科学基金(51575347;51405297;51204107)
【分类号】：TG111

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