The damaging micromechanisms in a pearlitic (EN-GJS700-2) Ductile Cast Iron (DCI) are investigated by means of Scanning Electron Microscope (SEM) analysis and Acoustic Emission (AE) testing. Monotonic uniaxial tensile tests are performed on microtensile specimens under strain control. SEM analysis is applied under in-situ conditions by means of a tensile holder. The multiple damaging micromechanisms are identified, and their evolution along with the mechanical response is characterised. The traditional AE features are found to be qualitatively correlated to the onset of the fracture damage over the elastic behaviour. The Information Entropy of the AEs evaluated according to both Shannon and Kullback-Leibler formulations is proven to be well correlated to the ongoing damage, and the incipient failure. Tentative failure criteria are finally proposed. The assessment approach is found to be promising for structural health monitoring purposes.

中文翻译：

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珠光体球墨铸铁损伤微观机制的表征和声发射测试的损伤评估

通过扫描电子显微镜 (SEM) 分析和声发射 (AE) 测试研究了珠光体 (EN-GJS700-2) 球墨铸铁 (DCI) 中的破坏性微观机制。单调单轴拉伸试验是在应变控制下对微拉伸试样进行的。SEM 分析是在原位条件下通过拉伸夹具进行的。确定了多种破坏性微观机制，并表征了它们随机械响应的演变。发现传统的 AE 特征与弹性行为的断裂损伤的发生定性相关。根据 Shannon 和 Kullback-Leibler 公式评估的 AE 的信息熵被证明与正在进行的损坏和初期故障密切相关。最后提出了暂定的失效准则。