Abstract This paper presents a novel multiscale approach for analyzing multi-axial stress-strain evolution in Ti-7Al cruciform specimens under dwell loading, through the use of an uncertainty-quantified, parametrically homogenized constitutive model (UQ-PHCM). The thermodynamically-consistent UQ-PHCM is built from rigorous upscaling of crystal plasticity FE models (CPFEM) using machine learning and uncertainty quantification. They explicitly incorporate microstructural information in the form of representative aggregated microstructural parameters (RAMPs). Uncertainty quantification accounts for uncertainty in model reduction, data sparsity and microstructural descriptors. This paper integrates advanced multiscale, multi-axial experiments with computational modeling at multiple scales to establish the UQ-PHCM as an effective tool for bridging the gap between laboratory specimen-scale experimental observations and micro-scale stresses and strains using CPFEM. The CPFEM is calibrated and validated by experimental data from surface strain measurements using digital image correlation (DIC) and grain-by-grain lattice strain measurements with in-situ far field high energy diffraction microscopy (ff-HEDM). A computational method is developed in CPFEM, to incorporate initial residual stresses consistent with measured lattice strains. The UQ-PHCM is validated with biaxial tensile dwell test results performed on the cruciform specimen with satisfactory prediction of gauge strain evolution in DIC measurements. Uncertainty in the strain field due to microstructural variability is also corroborated by the DIC measurements.

中文翻译：

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使用不确定性量化参数均质化本构模型对十字形驻留试验进行多尺度建模

摘要 本文提出了一种新的多尺度方法，通过使用不确定性量化的参数均质化本构模型 (UQ-PHCM) 来分析驻留载荷下 Ti-7Al 十字形试样的多轴应力-应变演变。热力学一致的 UQ-PHCM 是通过使用机器学习和不确定性量化对晶体塑性有限元模型 (CPFEM) 进行严格放大而构建的。它们以代表性聚合微观结构参数 (RAMP) 的形式明确地包含微观结构信息。不确定性量化解释了模型简化、数据稀疏性和微观结构描述符的不确定性。本文集成了先进的多尺度，多轴实验与多个尺度的计算建模，以建立 UQ-PHCM 作为弥合实验室样本尺度实验观察与使用 CPFEM 的微尺度应力和应变之间差距的有效工具。CPFEM 通过使用数字图像相关 (DIC) 和原位远场高能衍射显微镜 (ff-HEDM) 的逐粒晶格应变测量的表面应变测量的实验数据进行校准和验证。在 CPFEM 中开发了一种计算方法，以结合与测量的晶格应变一致的初始残余应力。UQ-PHCM 通过在十字形试样上进行的双轴拉伸保压试验结果进行验证，并在 DIC 测量中对应变演化进行了令人满意的预测。