Distributed Intrinsic Fabry-Pérot Fiber Interferometers for ultrasonic vibration measurement

A spiral bevel gear is subject to a special load in ultrasonic lapping, which is not only a processing object but also a processing tool, it is necessary to study dynamic characteristics of an ultrasonic vibration system. First, the spiral bevel gear is reasonably simplified to a frustum, which is then combined with a horn to form a new type of composite horn. Based on the theory of plane longitudinal wave propagation, the resonance mathematical model of the gear’s ultrasonic vibration system is established, and the frequency equation of the vibration system with gear characteristic parameters is obtained. Second, the frequency and displacement characteristics of an ultrasonic vibration system are analyzed by means of design examples, and the influence of the law of gear characteristic parameters on dynamic characteristics of the vibration system is studied. Finally, ultrasonic lapping and vibration measurement experiments are carried out using two pairs of different hypoid gears. The results show that the change in dynamic characteristics of an ultrasonic vibration system has a large influence on the finished machining quality of the gear. Therefore, it is necessary to consider the gear characteristic parameters when ultrasonic vibration system is designed. The research results provide an accurate theoretical basis for the detailed design of an ultrasonic lapping vibration system.

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Ultrasonic Vibration-Assisted Ball Burnishing Tool for a Lathe Characterized by Acoustic Emission and Vibratory Measurements

Materials ◽

10.3390/ma14195746 ◽

2021 ◽

Vol 14 (19) ◽

pp. 5746

Author(s):

Ismael Fernández-Osete ◽

Aida Estevez-Urra ◽

Eric Velázquez-Corral ◽

David Valentin ◽

Jordi Llumà ◽

...

Keyword(s):

Acoustic Emission ◽

Ultrasonic Vibration ◽

Vibration Measurement ◽

Ultrasonic Frequency ◽

Emission Measurement ◽

Ball Burnishing ◽

Burnishing Process ◽

Dynamic Techniques ◽

Vibration Assistance ◽

Low Amplitude

This paper focuses on a resonant system used to induce a low-amplitude movement and ultrasonic frequency to complement a ball burnishing process on a lathe. The system was characterized through the combination of different techniques. A full vibratory characterization of this process was undertaken with the purpose of demonstrating that the mechanical system—composed of the tool and the machine—does not present resonance phenomena during the execution of the operation that could lead to eventual failure. This dynamic analysis validates the adequateness of the tool when attached to an NC lathe, which is important to guarantee its future implementation in actual manufacturing contexts. A further aim was to confirm that the system succeeds in transmitting an oscillating signal throughout the material lattice. To this end, different static and dynamic techniques that measure different vibration ranges—including impact tests, acoustic emission measurement, and vibration measurement—were combined. An operational deflection shape model was also constructed. Results demonstrate that the only high frequency appearing in the process originated in the tool. The process was not affected by the presence of vibration assistance, nor by the burnishing preload or feed levels. Furthermore, the frequency of the assisting ultrasonic vibration was characterized and no signal due to possible damage in the material of the specimens was detected. These results demonstrate the suitability of the new tool in the vibration-assisted ball burnishing process.

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Multipoint Vibration Measurement Using Fabry-Perot Interferometers Consisting of Low-reflective Fiber Bragg Gratings Interrogated by Current Modulated Laser Diode

10.1364/ofs.2020.w4.31 ◽

2021 ◽

Author(s):

Koki Nakaya ◽

Bui Quoc Hung ◽

Koken Fukushima ◽

Manuel Guterres Soares ◽

Atsushi Wada ◽

...

Keyword(s):

Laser Diode ◽

Fiber Bragg Gratings ◽

Bragg Gratings ◽

Vibration Measurement ◽

Fabry Perot

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An In-Line Fiber Optic Fabry–Perot Sensor for High-Temperature Vibration Measurement

Micromachines ◽

10.3390/mi11030252 ◽

2020 ◽

Vol 11 (3) ◽

pp. 252

Author(s):

Dong Chen ◽

Jiang Qian ◽

Jia Liu ◽

Baojie Chen ◽

Guowen An ◽

...

Keyword(s):

High Temperature ◽

Fiber Optic ◽

Glass Tube ◽

Single Mode ◽

Vibration Sensor ◽

Vibration Measurement ◽

Voltage Sensitivity ◽

Hollow Silica ◽

Fabry Perot ◽

Radial Dimension

An in-line fiber optic Fabry–Perot (FP) sensor for high-temperature vibration measurement is proposed and experimentally demonstrated in this paper. We constructed an FP cavity and a mass on single-mode fibers (SMFs) by fusion, and together they were inserted into a hollow silica glass tube (HST) to form a vibration sensor. The radial dimension of the sensor was less than 500 μm. With its all-silica structure, the sensor has the prospect of measuring vibration in high-temperature environments. In our test, the sensor had a resonance frequency of 165 Hz. The voltage sensitivity of the sensor system was about 11.57 mV/g and the nonlinearity was about 2.06%. The sensor could work normally when the temperature was below 500 °C, and the drift of the phase offset point with temperature was 0.84 pm/°C.

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