Issue 75

A. Aabid et alii, Fracture and Structural Integrity, 75 (2025) 55-75; DOI: 10.3221/IGF-ESIS.75.06

(c) Mode III Figure 5: Confusion matrix for training and testing data for ETR

Decision Trees Regression Fig. 6 shows the confusion matrix for the DTR model throughout all modes for both training and testing datasets. The Mode I results show that the training matrix reveals strong performance for the 5 mm and 20 mm classes but more confusion for 10 mm and 15 mm, indicating that mid-range classes are harder to separate. The testing matrix reflects similar patterns with misclassifications between adjacent labels, especially 10 mm and 15 mm. Next, in the Mode II this model continues to show some confusion in the training data between 10 mm and 15 mm, while 5 mm and 20 mm are classified correctly. The testing matrix becomes more scattered, suggesting reduced generalization performance under shear conditions. Lastly, the Mode III training matrix shows consistent diagonal hits for higher crack lengths (15 mm and 20 mm) but increased errors for lower ones. The test matrix appears scattered, indicating that DTR struggles with prediction accuracy under Mode III loading.

(a) Mode I

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