MATERIALS TODAY COMMUNICATIONS, cilt.44, ss.1-24, 2025 (SCI-Expanded, Scopus)
This paper extensively examines the applicability of optimized ensemble machine learning (ML) algorithms via
grey wolf optimization (GWO) to estimate the tensile performance of polyethylene fiber-reinforced engineered
cementitious composites (PE-ECC). A robust and credible dataset is utilized for the establishment of the models
based on available studies in the literature: The dataset includes 132 instances of PE-ECC mixes with 11 input
features and 2 target output. Moreover, feature importance, Shapley additive explanation (SHAP) and partial
dependence (PDP) analyses are implemented to enhance the explainability of the estimation models and to
address the “black box” challenge of ML models. Based on the obtained results, the optimized extreme gradient
boosting (XGBoost) and categorical boosting (CatBoost) models with GWO estimated the tensile performance of
PE-ECC more effectively and accurately in comparison with other ensemble models. This has been extensively
evaluated and proved through various approaches such as performance indicators, Taylor diagram, error analysis,
and score analysis. To give a quantitative example, in the testing phase, for the prediction of tensile strain
capacity, the GWO-XGBoost model reached the highest accuracy values with R2= 0.785 and RMSE= 1.077,
whereas for the GWO-CatBoost model, these performance indicators were 0.764 and 1.129, respectively. In terms
of tensile strength prediction, the GWO-XGBoost model achieved a high prediction accuracy with R2= 0.930 and
RMSE= 1.004, while for the GWO-CatBoost model, R2 and RMSE were 0.932 and 0.987, respectively. Meanwhile,
SHAP and PDP analyses were employed to identify the most influential features on output, and thus
providing precious insight for designers to improve the tensile performance of PE-ECC. Additionally, a userfriendly
graphical user interface (GUI) was constructed for estimating the tensile performance of PE-ECC and
validated with new experimental datasets, illustrating the efficiency of the models. All in all, the importance of
this work highlights the superior performance of the advanced GWO-ML models and GUI for estimating the
tensile performance of PE-ECC and is thought to be a valuable contribution for further research in this area.