Application phase analysis for predicting high-speed crack propagation/arrest in 3D thick plates using S-version FEM

• A prediction strategy of high-speed crack propagation in 3D plates was developed. • An s-method-based dynamic crack propagation model was employed for simulations. • Application phase analysis was performed to predict crack behaviours. • An optimisation algorithm was proposed for the application phase analysis. • The strategy was validated through experiments on PMMA specimens. Thick plate structures are integral to numerous large-scale engineering systems, making the propagation of brittle cracks within these plates a critical safety issue. This study introduces a strategy using the s-version finite element method (s-method) tailored for application phase analysis, which is designed to predict the behaviour of high-speed crack propagation/arrest in three-dimensional thick plate structures. The proposed strategy consists of two segments: the first focuses on predicting the crack behaviour after crack initiation, while the second predicts the following overall high-speed crack propagation/arrest behaviour. To achieve this, an optimisation algorithm integrating the Non-linear Gradient Descent and Golden Section methods is employed in both segments to predict the detailed high-speed crack propagation/arrest behaviour. To validate the proposed strategy, experiments were conducted using double cantilever beam-type plate specimens made of polymethyl methacrylate, with predictions compared against experimental data. The results indicated that the strategy successfully reproduced the behaviour of high-speed crack propagation/arrest in three-dimensional thick plate structures, including the crack velocity oscillations likely due to specimen vibrations. Additionally, the normalised error further underscores the strategy’s effectiveness. Consequently, this strategy could potentially establish a robust numerical foundation for predicting high-speed crack behaviours in various engineering structures.