Phenomenological models are commonly used to model void nucleation from second phase particles in ductile fracture simulations. Parameters in these continuum models are typically estimated using indirect methods, by comparison with experimental fracture data. In this paper, a novel approach based on acoustic emission (AE) measurements in smooth and notched bar tension tests is proposed to estimate void nucleation model parameters such as the mean and standard deviation of the nucleation strains. Tensile tests on AA 7075-T651 specimens combined with AE data establish a robust correlation between AE amplitude and the average void nucleation rate. The nucleation parameters are calibrated using a dog-bone tensile specimen. Simulations using these calibrated parameters accurately reproduces AE amplitude trends in other specimen geometries. This approach provides a promising alternative to traditional calibration methods, enhancing the reliability and adaptability of void growth based ductile fracture models.

中文翻译：

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基于声发射的延性断裂模型中空洞成核的表征

唯象模型通常用于模拟延性断裂模拟中第二相颗粒的空洞成核。这些连续体模型中的参数通常使用间接方法通过与实验断裂数据进行比较来估计。在本文中，提出了一种基于光滑和缺口钢筋拉伸试验中声发射（AE）测量的新方法来估计空穴成核模型参数，例如成核应变的平均值和标准偏差。 AA 7075-T651 样品的拉伸测试与 AE 数据相结合，建立了 AE 振幅与平均空洞成核率之间的稳健相关性。使用狗骨拉伸样品校准成核参数。使用这些校准参数进行的模拟可以准确地再现其他样本几何形状中的 AE 振幅趋势。这种方法为传统校准方法提供了一种有前景的替代方法，增强了基于空洞生长的延性断裂模型的可靠性和适应性。