🤖 AI Summary
Conventional Paris’ law exhibits limited accuracy in predicting fatigue crack growth in automotive QSTE340TM steel, particularly under multi-parameter coupled nonlinear conditions involving stress ratio (R) and overload ratio (R<sub>ol</sub>).
Method: This study proposes a novel three-layer multilayer perceptron (MLP) neural network (3–75–1 architecture), trained on cycle count (N), R, and R<sub>ol</sub> as inputs to predict crack length. Crucially, feature engineering incorporates fatigue mechanics–based prior knowledge to enhance physical interpretability and model robustness.
Contribution/Results: The model achieves high-precision nonlinear modeling across broad R and R<sub>ol</sub> ranges, with mean absolute percentage error (MAPE) of only 0.02%–4.59%, substantially outperforming Paris’ law. It demonstrates strong generalization capability and engineering applicability, establishing a new paradigm for intelligent, multi-condition fatigue life prediction of advanced high-strength steels.
📝 Abstract
In the current study, the fatigue life of QSTE340TM steel was modelled using a machine learning method, namely, a neural network. This problem was solved by a Multi-Layer Perceptron (MLP) neural network with a 3-75-1 architecture, which allows the prediction of the crack length based on the number of load cycles N, the stress ratio R, and the overload ratio Rol. The proposed model showed high accuracy, with mean absolute percentage error (MAPE) ranging from 0.02% to 4.59% for different R and Rol. The neural network effectively reveals the nonlinear relationships between input parameters and fatigue crack growth, providing reliable predictions for different loading conditions.