In this research, vibration frequency analysis of three layered functionally graded material (FGM) cylinder-shaped shell is studied with FGM central layer and the internal and external layers are of homogenous material. Strain and curvature-displacement relations are taken from Sander's shell theory. The shell frequency equation is obtained by employing the Rayleigh Ritz method. Influence on natural frequencies (NFs) is observed for various thickness of the middle layer. The characteristics beam functions are used to estimate the dependence of axial modal. Results are obtained for thickness to radius ratios and length to radius ratios for different edge conditions. The validity of this method is checked for numerous results in the open literature.
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http://dx.doi.org/10.1038/s41598-018-38122-0 | DOI Listing |
J Voice
January 2025
Department of Audio, Video, and Electronic Forensics, Academy of Forensic Science, Shanghai, China; Shanghai Forensic Service Platform, Key Laboratory of Forensic Science, Ministry of Justice, Shanghai, China.
Drug abuse can cause severe damage to the human speech organs. The vocal folds are one of the important speech organs that produce voice through vibration when airflow passes through. Previous studies have reported the negative effects of drugs on speech organs, including the vocal folds, but there is still limited research on relevant field.
View Article and Find Full Text PDFRev Sci Instrum
January 2025
School of Perceptual Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, China.
This paper presents a flat-type piezoelectric motor utilizing in-plane vibration modes. Two piezoelectric ceramic plates in combination with a brass metal sheet were used to construct the stator. The superposition of two second order in-plane vibration modes can generate a traveling-wave inside the stator.
View Article and Find Full Text PDFJ Chem Phys
January 2025
State Key Laboratory of Physical Chemistry of Solid Surfaces, Collaborative Innovation Center of Chemistry for Energy Materials, Fujian Provincial Key Laboratory of Theoretical and Computational Chemistry, and Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, People's Republic of China.
Vibro-polaritons are hybrid light-matter states that arise from the strong coupling between the molecular vibrational transitions and the photons in an optical cavity. Developing theoretical and computational methods to describe and predict the unique properties of vibro-polaritons is of great significance for guiding the design of new materials and experiments. Here, we present the ab initio cavity Born-Oppenheimer density functional theory (CBO-DFT) and formulate the analytic energy gradient and Hessian as well as the nuclear and photonic derivatives of dipole and polarizability within the framework of CBO-DFT to efficiently calculate the harmonic vibrational frequencies, infrared absorption, and Raman scattering spectra of vibro-polaritons as well as to explore the critical points on the cavity potential energy surface.
View Article and Find Full Text PDFSci Rep
January 2025
College of Engineering, Arab Academy for Science, Technology and Maritime Transport, Alexandria, Egypt.
Bladeless wind turbines face operational limitations due to the lock-in phenomenon. This study introduces two novel mechanisms for designing bladeless wind turbines to address this issue, enabling operation across a broad wind speed range from 2 to 10 m/s while ensuring that lock-in conditions are satisfied at any wind speed within this range. The study aims to maintain optimal performance without any decline that is observed in conventional bladeless wind turbines by controlling the turbine's natural frequency through implementing these mechanisms, either by adjusting the effective length of the stand or by incorporating an additional mass in the hollow mast, or both.
View Article and Find Full Text PDFSci Rep
January 2025
School of Physics and Optoelectronic Engineering, Key Laboratory of Gravitational Wave Precision Measurement of Zhejiang Province, Taiji Laboratory for Gravitational Wave Universe, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Hangzhou, 310024, China.
In this paper, a fixed support method for a cryogenic monocrystalline silicon Fabry-Pérot cavity of an ultra-stable laser for space applications is proposed. Through finite element analysis, the vibration sensitivity at the center of the cavity is below 10E-12/g; the fundamental frequency is 381 Hz; the thermal deformation is compensated by applying a preload force of about 3 N*m for a variation of 300 K to 124 K. Based on these analyses, an equal-mass cavity simulator was machined and mounted.
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