Abstract This paper proposes a new approach on the identification of plastic anisotropic properties (σY, n, m), which is based on new modified expanding cavity model (ECM). The new ECM incorporates Hill's an anisotropic yield criterion in 1948 by equivalent transformation of stress expression form from spherical polar coordinate system to space rectangular coordinate system, and considers piling-up or sinking-in effect by introducing volume correction factor t as a semi-theoretical function. Through the indentation analysis for new ECM, the representative stress-strain method can characterize indentation mean pressure and uniaxial flow properties. Meanwhile, nonlinear functional relations between indentation response and plastic anisotropic properties are established. The effectiveness and reliability of new developed ECM approach are verified by the comparisons between identified properties and input properties in spherical indentation simulations, the comparisons between plastic anisotropic properties identified from instrumented indentation experiments and uniaxial compression experiments, and the comparisons between representative flow stress-strain points and compression experimental curves. The identified results are obtained by iterative calculations using the trust-region techniques based on the nonlinear least-square method. Excellent agreement is achieved. Finally, it is demonstrated that the proposed approach is reliable and useful for identification of plastic anisotropic properties of various anisotropic materials.

中文翻译：

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一种通过球形压痕识别塑性各向异性的改进 ECM 方法

摘要 本文提出了一种新的塑性各向异性特性(σY, n, m) 识别方法，该方法基于新的修正膨胀腔模型(ECM)。新的 ECM 将 1948 年希尔的各向异性屈服准则从球面极坐标系等效变换到空间直角坐标系，并通过引入体积校正因子 t 作为半理论考虑堆积或下沉效应功能。通过对新型 ECM 的压痕分析，具有代表性的应力应变方法可以表征压痕平均压力和单轴流动特性。同时，建立了压痕响应与塑性各向异性之间的非线性函数关系。新开发的 ECM 方法的有效性和可靠性通过球形压痕模拟中识别属性和输入属性之间的比较、仪器压痕实验和单轴压缩实验中识别的塑性各向异性属性之间的比较以及代表性流动应力-应变之间的比较得到验证。点和压缩实验曲线。识别结果是通过使用基于非线性最小二乘法的信任域技术的迭代计算获得的。达成了极好的协议。最后，证明了所提出的方法对于识别各种各向异性材料的塑性各向异性特性是可靠且有用的。