This issue aims to collect invited articles on any topics from basic research to application within acoustical science and engeering.
Professor Shiu-Keung Tang
Submission Deadline: 30 August 2019
Manuscripts should be submitted online through Hapres Online Submission System. Please visit Guide for Authors before submitting a manuscript. Authors are encouraged to submit a paper as soon as it is ready and don’t need to wait until the deadline. Submissions will be sent to peer-review in order of arrival. Accepted papers will be published continuously in Med One and then gathered together on the special issue webpage. We welcome Research articles, Review papers and Perspectives. There are no word limits for each article type. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for approval.
Type of Paper: Original Research Article
Paper Title: Acoustics of Quenching
Authors: Jurij Prezelj, Jure Murovec, Luka Curovic, Tadej Novakovic
Abstract: The following paper describes the two possibilities of applying acoustics into the heat treatment of materials. The first application describes the monitoring of sound generated by a quenching process, and the second, the introduction of strong ultrasound to influence the process itself. The sound in a cooling liquid, generated by the quenching process, was experimentally analyzed. Sound signals were recorded with a hydrophone and temporal Fourier transformation was performed. Results indicate that sound signals can be used for monitoring the quenching process in a real time. A significant change of the acoustic signal shape corresponds to the transition from a saturated boiling to a sub-cooled boiling. The process of quenching can be adjusted by using different process parameters, such as cooling liquid characteristics, the velocity of the cooling liquid flow, its temperature, etc. The following article presents a new approach to adjusting the quenching process by using a high intensity ultrasound. Results show that a high intensity ultrasound affects the heat transfer from the red-hot specimen surface into the cooling liquid in the early stage of quenching, and it can be used as a method for adjusting the hardening process.
Keywords: ultrasound, sound pressure level, steel hardening, saturated boiling, sub-cooled boiling, quenching
Type of Paper: Original Research Article
Paper Title: Diagnosis of bearing faults based on the low-rank and sparse model of the vibration signal
Authors: Liang Yu1, Wei Dai2, Jerome Antoni3, Shichun Huang1, Quentin Leclere3, Weikang Jiang1
Abstract: The failure of rolling element bearings is one of the most frequent reasons for machine breakdown. It has prompted a great deal of research on developing new algorithms to solve the problem of vibration-based diagnostics of rolling element bearings. At the stage of a failure, the measured vibration signal typically consists of a series of repetitive transients immersed in background noise. In order to extract transient signals from strong additive noise, a low-rank and sparse decomposition-based method was proposed. First, the low dimensional representation of the signal is calculated by two time-frequency analysis methods, Gabor transform and synchrosqueezing transform. Moreover, the influence of the choice of sparse representation matrix on our diagnosis algorithm is also discussed. Then, Robust principal component analysis (RPCA) is used to decompose the sparse time-frequency representation matrix into a low-rank matrix and a sparse matrix. Under different sparse representations, transient signals and noise will show different low-rank and sparse characteristics, which will be discussed in the paper. Finally, the transient signal is recovered by using the decomposed matrix and the recovered signal is used for fault diagnosis. In this paper, the performance of the proposed method will be tested on both synthetic and real vibration signals and the results show the algorithm is effective and robust.
Keywords: vibration-based diagnostics of rolling element bearings; transient signals; low dimensional representation; low-rank decomposition
Virtual Special Issue (VSI) is a collection of papers centered around a specific topic, led by an expert (Guest Editor) in the field. Virtual Special Issues are an important component of our journal and cover current hot topics within the scope of the journal.
All papers belonging to a Virtual Special Issue will be gathered together on a single webpage. They are published in the regular issues of the journal as soon as publishable, and labeled as belonging to the Virtual Special Issue. A link from each paper will take you to the Virtual Special Issue website.
Submissions to Virtual Special Issues will undergo the same rigorous peer-review process as regular papers submitted to the journal.
The Hong Kong Polytechnic University, Hong Kong