Damage measurement of materials is a crucial challenge for researchers and engineers in manufacturing industries. In this study, based on the image processing technique, a developed approach for determining the Lemaitre’s ductile damage parameter by the direct measurement method is proposed. For this purpose, first, the micrographs pictures are provided by a scanning electron microscope to attain the damage evolution behavior of St37 steel. Then, prediction results of the suggested method and the Lemaitre’s direct approach as well as the microhardness technique and also a lately published numerical method in damage propagation, crack initiation, and ductile fracture of a few tensile samples are compared with the corresponding experimental tests. The comparison reveals the higher efficiency and accuracy of the current approach. Therefore, it is concluded that the new presented method is a reliable approach to achieve the Lemaitre’s ductile damage parameter and predict the damage evolution behavior of ductile materials.

中文翻译：

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一种增强的延性损伤直接测量方法


材料的损伤测量对于制造业的研究人员和工程师来说是一个重大挑战。本研究基于图像处理技术，提出了一种直接测量法确定勒梅特延性损伤参数的方法。为此，首先通过扫描电子显微镜提供显微照片，以获得St37钢的损伤演化行为。然后，将所提出的方法和勒梅特直接方法以及显微硬度技术和最近发表的数值方法对几个拉伸样品的损伤扩展、裂纹萌生和延性断裂的预测结果与相应的实验测试进行了比较。比较表明当前方法具有更高的效率和准确性。因此，得出的结论是，新提出的方法是获得勒梅特延性损伤参数并预测延性材料损伤演化行为的可靠方法。