High speed Holographic Shape and Vibration Measurement of the Semi-transparent Tympanic Membrane

2021 ◽  
pp. 67-71
Author(s):  
Haimi Tang ◽  
Pavel Psota ◽  
John J. Rosowski ◽  
Jeffery T. Cheng ◽  
Cosme Furlong
Keyword(s):  
Tympanic Membrane ◽  
High Speed ◽  
Vibration Measurement

An improved model for investigating the vibration characteristics of ball bearing owing to outer race waviness under high speed

2021 ◽  
Vol 69 (2) ◽  
pp. 89-101
Author(s):  
Pingping Hou ◽  
Liqin Wang ◽  
Zhijie Xie ◽  
Qiuyang Peng
Keyword(s):  
High Speed ◽  
Ball Bearing ◽  
Vibration Measurement ◽  
Vibration Frequencies ◽  
Outer Race ◽  
Response Characteristics ◽  
Lagrange’S Equation ◽  
Rolling Elements ◽  
Initial Clearance ◽  
Improved Model

In this study, an improved model for a ball bearing is established to investigate the vibration response characteristics owing to outer race waviness under an axial load and high speed. The mathematical ball bearing model involves the motions of the inner ring, outer ring, and rolling elements in the radial XY plane and axial z direction. The 2Nb + 5 nonlinear differential governing equations of the ball bearing are derived from Lagrange's equation. The influence of rotational speed and outer race waviness is considered. The outer race waviness is modeled as a superposition of sinusoidal function and affects both the contact deformation between the outer raceway and rolling elements and initial clearance. The MATLAB stiff solver ODE is utilized to solve the differential equations. The simulated results show that the axial vibration frequency occurred at l fc and the radial vibration frequencies appeared at l fc fc when the outer race waviness of the order (l) was the multiple of the number of rolling elements (k Nb) and that the principal vibration frequencies were observed at l fc fc in the radial x direction when the outer race waviness of the order (l) was one higher or one lower than the multiple of the number of rolling elements (k Nb 1). At last, the validity of the proposed ball bearing model was verified by the high-speed vibration measurement tests of ball bearings.

A New Dual-Channel Analyzer for Vibration of Rotary Machine

2008 ◽  
Author(s):  
Qing He ◽  
Dongmei Du
Keyword(s):  
Vibration Analysis ◽  
High Speed ◽  
Integral Transform ◽  
Vibration Measurement ◽  
Waveform Analysis ◽  
Rotating Speed ◽  
Rotary Machine ◽  
Vibration Sensors ◽  
Dual Channel ◽  
Channel Analyzer

A new simultaneous sampling and analyzer for dual-channel signal of vibration for rotating machine is developed based on the C8051F060, which is a high-speed SoC system and has two ADCs embedded with high sampling frequency. The signal condition circuits for various vibration sensors are designed, such as charge amplifier, integral transform and rotating speed detector. A colorful TFT LCD used can display all kinds of vibration analysis plots that are friendly in human-machine interface. The large capability non-volatile memory is used to restore up to one hundred of group of vibration waves. With many typical functions of vibration analysis, including waveform analysis, spectrum, orbit and balancing, this instrument is widely applied to vibration measurement and fault diagnosis of machine and equipment, especially for field balancing of rotary machine.

scholarly journals Structural Improvement of the ω-Type High-Speed Rail Clip Based on a Study of Its Failure Mechanism

2019 ◽  
Vol 2019 ◽  
pp. 1-14 ◽  
Author(s):  
Xiaogang Gao ◽  
Anbin Wang ◽  
Yu He ◽  
Xiaohan Gu
Keyword(s):  
Failure Mechanism ◽  
Fatigue Test ◽  
High Frequency ◽  
High Speed ◽  
Excitation Frequency ◽  
Test System ◽  
Vibration Measurement ◽  
High Speed Rail ◽  
Resonant Frequencies ◽  
Rail Wear

In the circumstances of high-speed railways, the wheel-rail vibration is significantly aggravated by polygonal wheel wear and rail corrugation, which subsequently leads to the wheel-rail interaction at higher frequencies and potential failure of the rail fastening. In this paper, a ω-type clip of the fastening in the CRH high-speed rail was used to investigate the failure mechanism. First, a dynamic wheel-rail coupling model and a finite element analysis of the rail clip were developed, from which the rail vibration frequency and modal frequencies of the clip with different installation torques were obtained. The experimental tests and modal simulation results were mutually verified. In addition, the real-time vibration measurement and the wheel-rail wear monitoring were carried out at a CRH high-speed railway site. It was found that the resonant frequencies of the ω-type clip in the installation condition coincided with the excitation frequencies of the wheel-rail interaction induced by wheel-rail wear. The high-frequency dynamic failure mechanism of a typical ω-type clip, W300-1, is put forward for the first time. Moreover, a high-frequency rail clip fatigue test system was designed and developed specifically for this study. The loading excitation frequency of the clip test used was set as 590 Hz, and the loading amplitude was 0.05 mm. After 125-minute operation of the test system, the clip was broken at the expected location predicted by the FEA model. The high-frequency fatigue test result further verified that the failure mechanism of the ω-type clip was due to the resonance of the clip with its excitation force from the wheel-rail interaction. Finally, the clip was then structurally improved taking into account the stiffness and mass, which led to its resonant frequencies shifting away from the high-frequency excitation range, hence avoiding resonance failure of the subject clip.

Research on Dynamic Design Method Based on Measuring Information for Printing Press

2010 ◽  
Vol 174 ◽  
pp. 290-294
Author(s):  
Yi Ming Wang ◽  
Bang She Chen ◽  
Yan Li ◽  
Shao Hua Zhang
Keyword(s):  
Theoretical Model ◽  
Dynamic Characteristics ◽  
High Speed ◽  
Design Method ◽  
Model Analysis ◽  
Printing Press ◽  
Vibration Measurement ◽  
Dynamic Design ◽  
Analysis Experiment ◽  
Printing Machine

Printing machinery’s reliability is one of the most important index parameter and good dynamic characteristics are essential for high speed printing press. The dynamic characteristic is predictable for printing machine with dynamic design. With the complexity of printing technique and printing machine, information, such as load on components is lack, leading to the difficulty of dynamic model solving and further more the dynamic parameters needs to be verified. Firstly, according to the dynamic design method, a dynamic design process based on measuring information for printing machine was put forward. Secondly, on the basis of principle and structure analysis to typical printing machine, dynamic characteristics measurement item and method was determined. With a wallboard of a two-color offset press acting as an example, the utilizing method was illustrated through dynamic modeling, theoretical model analysis, experiment model analysis based on vibration measurement and comparing the theoretical and experimental results. Finally, a Dynamic Design Assistant Platform based Vibration Measurement for Printing Machine was developed and had been used in 10 kinds of printing machine measurement and analysis. The conclusion shows that the tolerance of the theoretical model analysis results and experiment results is allowed. A new approach for new printing machine design and optimal design for existed printing machine is given.

scholarly journals Full-field transient vibrometry of the human tympanic membrane by local phase correlation and high-speed holography

2014 ◽  
Vol 19 (9) ◽  
pp. 096001 ◽  
Author(s):  
Ivo Dobrev ◽  
Cosme Furlong ◽  
Jeffrey T. Cheng ◽  
John J. Rosowski
Keyword(s):  
Tympanic Membrane ◽  
High Speed ◽  
Phase Correlation ◽  
Local Phase ◽  
Full Field ◽  
Human Tympanic Membrane

Analyses of the Tympanic Membrane Impulse Response Measured with High-Speed Holography

2021 ◽  
pp. 108335
Author(s):  
H. Tang ◽  
P. Psota ◽  
J.J. Rosowski ◽  
C. Furlong ◽  
J.T. Cheng
Keyword(s):  
Tympanic Membrane ◽  
Impulse Response ◽  
High Speed

Digital Speckle Projection for Vibration Measurement by Applying Digital Image Correlation Method

2006 ◽  
Vol 326-328 ◽  
pp. 99-102 ◽  
Author(s):  
Fu Jun Yang ◽  
Xiao Yuan He
Keyword(s):  
Digital Image Correlation ◽  
Digital Image ◽  
High Speed ◽  
Speckle Pattern ◽  
Plane Deformation ◽  
Correlation Method ◽  
Image Correlation ◽  
Vibration Measurement ◽  
Digital Image Correlation Method ◽  
Digital Speckle

Digital image correlation method (DICM) is described as a robust in-plane deformation measuring method due to its simple optical setup and the insensitivity against ambient noise. Based on DICM, digital speckle projection has been developed for shape measurement. This paper explores the possibilities for vibration analysis using digital speckle projection together with DICM. A digital speckle pattern, generated by computer, is projected on an object surface using an LCD projector. Then the dynamic deformation modulated speckle images are captured by a high-speed CCD camera and saved in the computer. By using the self-developed temporal sequence digital images correlation algorithm, the deformation and vibration mode can be analyzed quantitatively. The proposed method avoids using stroboscopic or laser illumination and simplifies the experimental setup for vibration measurement, while it is time-consuming thanks to calculating a large amount of correlation coefficients. The experimental performance on a harmonic-vibrating cantilever beam well demonstrates the validity of the new method.

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