Fatigue behavior analysis and life prediction of all-composite joint

• Published in: Thin-walled structures 2023-02, Vol.183, p.110320, Article 110320
• Main Authors: Yao, Chenxi, Qi, Zhenchao, Chen, Wenliang
• Format: Article
• Language: English
• Subjects: Composite joints; Fatigue behavior; Joining techniques; Thermoplastic composite
• ISSN: 0263-8231
• DOI: 10.1016/j.tws.2022.110320

In this study, we join the thermoplastic composite using thermoplastic composite fastener (TPCF), and a physics-guided neural network is designed to predict the fatigue life of the all-composite joint. The experimental results show that TPCF is only 19.0% of the weight of the titanium rivet. Under a proper joining pressure of 1.50 MPa, the all-composite joint is well connected by an ‘S-shape’ interlayer, the fatigue resistance is improved. After hot-press joining, the lower cooling rate of 1 °C/min prolongs the crystallization process of TPCF and composite hole wall, thus enhancing the fatigue life to 105.8 cycles. The experimental results are summarized as physics constraints guiding the neural network. Similar fatigue data are migrated by producing a significant constraint. The loss function is the negative logarithm of the likelihood, which can predict both mean and deviation of fatigue life. The predicted results agree well with the experiments. •Innovating a light-weight and high-strength all-composite joint by joining thermoplastic composite with thermoplastic composites fastener (TPCF).•Developing a physics-guided neural network fusing physical knowledge and migration data to predict the fatigue life of all-composite joints.