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

초록

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.

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