Abstract Defects including inclusions and voids significantly affect the mechanical properties of the additive manufacturing materials. It is necessary to precisely capture the defects and determine their hazardous effects on material mechanical properties. In this paper, a damage model is developed to describe the nucleation, growth, and coalescence of voids in additive manufacturing materials, revealing the nature of true stress drop. In order to characterize the defect morphology and depict the defect evolution, an in-situ tensile test with synchrotron radiation X-ray topography (SRXT) is carried out. Statistical reconstruction of the initial voids morphology are used as input for the established damage model. Furthermore, in light of the epistemic uncertainty in the process of defect reconstruction in SRXT, Bayesian framework is adopted for parameter estimation. Finally, the above model is verified by the data form 3D defect reconstruction and the uniaxial tensile test, where the constitutive behavior as well as its scatter are well captured. This work contributes to the depiction on damage evolution and the correspondingly affected deformation performance, which can be useful in material design and defect control for additive manufactured load-bearing structures.

中文翻译：

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基于同步辐射X射线断层扫描缺陷演化观察的增材制造部件力学行为预测

摘要 夹杂物和空隙等缺陷对增材制造材料的力学性能有显着影响。有必要精确捕获缺陷并确定它们对材料机械性能的有害影响。在本文中，开发了一种损伤模型来描述增材制造材料中空隙的成核、生长和聚结，揭示真实应力降的本质。为了表征缺陷形态并描绘缺陷演变，进行了同步辐射X射线形貌（SRXT）的原位拉伸试验。初始空隙形态的统计重建用作建立的损伤模型的输入。此外，鉴于 SRXT 中缺陷重建过程中的认知不确定性，参数估计采用贝叶斯框架。最后，通过 3D 缺陷重建和单轴拉伸试验的数据形式验证了上述模型，其中本构行为及其散射被很好地捕获。这项工作有助于描述损伤演化和相应影响的变形性能，可用于增材制造承重结构的材料设计和缺陷控制。