https://journals.bilpubgroup.com/index.php/jmmmr/issue/feed 2024-11-27T13:02:05+08:00 Managing Editor: Echo Young jmer@bilpublishing.com Open Journal Systems <p>ISSN: 2810-935X(Online)</p> <p>Email: jmer@bilpublishing.com</p> https://journals.bilpubgroup.com/index.php/jmmmr/article/view/7906 2024-11-27T13:02:05+08:00 Tong Zhou zhoutong@airchinacargo.com Guojun Zhang ez900113@gmail.com Yiqun Cai yiqun.cai@ufl.edu

<p>Bearings are crucial components in aircraft power systems and mechanical structures, and their complex fault characteristics significantly impact flight safety. To improve the accuracy of aircraft bearing fault diagnosis, this paper proposes a novel diagnostic method based on optimized Variational Mode Decomposition (VMD) and Generalized Multi-Scale Fuzzy Entropy (GMFE). First, the Moth-Flame Optimization (MFO) algorithm is used to optimize the two parameters of the VMD signal decomposition method—the number of modes and the penalty factor —to obtain the optimal parameter combination . This optimized VMD method is then applied for signal decomposition and reconstruction of bearing vibration signals. Next, the GMFE entropy algorithm is employed to extract fault features from the reconstructed signals, resulting in the required set of bearing fault feature vectors. Finally, the extracted feature vector set is input into a Support Vector Machine (SVM) model for classification and diagnosis of aircraft bearing faults. Experimental results indicate that the proposed method effectively enhances the identification accuracy of bearing diagnosis and demonstrates excellent fault feature extraction capabilities.</p>

2024-03-09T00:00:00+08:00 Copyright © 2024 Tong Zhou, Guojun Zhang, Yiqun Cai https://journals.bilpubgroup.com/index.php/jmmmr/article/view/6050 2023-12-26T17:22:21+08:00 Hüseyin Fırat Kayiran huseyinfirat.kayiran@tkdk.gov.tr

<p>In this study, a composite disc with Epoxy (T300) material was considered. It is possible to come across different studies to examine the stress field on disks rotating or stationary under thermal loads. Discs play a vital role in the assembly of machine parts in industry. Knowing the behavior of machine parts against temperature allows very good data to be transferred to today’s artificial intelligence world. Epoxy materials are very important today. Epoxies are made up of very strong fibers. They are used in unmanned aerial vehicles, spacecraft and the rocket industry. In addition, their maximum and minimum hardening properties, good adhesion properties and wear resistance are also quite high. In this study, an Epoxy disk (T300) subjected to linear increasing temperature was modeled. The stresses obtained on the discs were determined by different methods. As can be seen from the results, for a temperature of 150 °C, the average stress, strain and compression occurring sequentially in the inner and outer regions of the disk acts as 215.06 and –443.90 MPa. According to the results obtained, it was concluded that there are parallel increases in stresses as the temperature increases, and this can be proven by other different studies in the literature.</p>

2024-02-28T00:00:00+08:00 Copyright © 2024 Author(s)