Nickel-based single-crystal (SC) superalloys exhibited excellent exceptional mechanical properties at high temperatures due to the elimination of internal grain boundaries, contributed a strong orientation-dependent material response. The anisotropy of SC superalloys was modeled viscoplastically from a macroscopic viewpoint based on the Kelvin decomposition theory [1] which was a decomposition of the stress space according to the elastic matrix eigen-directions to control the viscoplastic flow by Kelvin stress decoupled from each other. Compared to the classical phenomenological macro model, the proposed model effectively captures the slip deformation mechanism of SC superalloys with the inherent ability to simulate anisotropic because of the two criterions framework controlled by Kelvin stress. Compared with others, the proposed model was able to simulate time-dependent inelastic deformation and cyclic deformation behavior under complex loading. The kinematic hardening and isotropic hardening models incorporated microscopic quantities, such as dislocation density and channel phase width, connecting the macroscopic mechanical response with the microscopic state to achieve multiscale constitutive modelling. The parameter identification and finite element implementation were conducted on a SC superalloy [2]. Simulation results demonstrated the accuracy of the proposed model in predicting deformation behavior under various orientations, rate-dependent effects, isothermal and non-isothermal cyclic deformation. Comparison with the classical anisotropic matrix macroscopic phenomenological approaches highlights the superior capability of the proposed model to simulate the orientation-dependent mechanical properties of single-crystal alloys.

中文翻译：

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基于开尔文分解的镍基单晶高温合金各向异性循环塑性本构建模


由于消除了内部晶界，镍基单晶 （SC） 高温合金在高温下表现出优异的优异机械性能，有助于产生强烈的取向依赖性材料响应。基于开尔文分解理论 [1] 从宏观角度对 SC 高温合金的各向异性进行建模，该理论是根据弹性基体特征方向分解应力空间，以通过开尔文应力相互解耦来控制粘塑性流动。与传统的现象学宏观模型相比，所提出的模型有效地捕捉了 SC 高温合金的滑移变形机制，由于开尔文应力控制的两个准则框架，该模型具有模拟各向异性的固有能力。与其他模型相比，所提出的模型能够模拟复杂载荷下随时间变化的非弹性变形和循环变形行为。运动学硬化和各向同性硬化模型结合了微观量，例如位错密度和通道相位宽度，将宏观机械响应与微观状态联系起来，以实现多尺度本构建模。参数识别和有限元实施是在 SC 高温合金 [2] 上进行的。仿真结果表明，所提出的模型在预测各种方向、速率依赖效应、等温和非等温循环变形下的变形行为方面的准确性。与传统各向异性基体宏观现象学方法的比较突出了所提出的模型在模拟单晶合金的方向依赖性机械性能方面的卓越能力。