scholarly journals An Experimental Study of the Vibrational Characteristics of a Diamond Circular Blade Using Electronic Speckle-Pattern Interferometry and FEM

2021 ◽  
Vol 15 (1) ◽  
pp. 16-23
Author(s):  
Mykhaylo Tkach ◽  
Yurii Halynkin ◽  
Arkadii Proskurin ◽  
Irina Zhuk ◽  
Volodymyr Kluchnyk ◽  
...  
Keyword(s):  
Mean Squared Error ◽  
Speckle Pattern ◽  
Speckle Interferometry ◽  
Mode Shapes ◽  
Electronic Speckle Pattern Interferometry ◽  
Minimum Mean Squared Error ◽  
Program Calculation ◽  
Vibrational Characteristics ◽  
Electronic Speckle Interferometry ◽  
Inner Diameter

Abstract The compact installation and technology for determining vibration characteristics by the ESPI method has been created. The experimental determination of the dynamic characteristics of a diamond circular blade with a diameter of 203.4 mm and a thickness of 1.19 mm using real-time electronic speckle interferometry is presented. 15 mode shapes of vibration were detected in the range from 100 to 5000 Hz. The program calculation of the natural frequencies and mode shapes is carried out for three values of the clamping inner diameter (42 mm, 44 mm, 46 mm). The options for calculating a disk with a rim and without a rim are considered. It is shown that the minimum mean squared error of the calculation is achieved for the values of the diameter of the disk 46 mm, 42 mm and 44 mm for the number of nodal circles 0, 1 and 2, respectively. To verify the accuracy of the interferometer, experimental, computational and analytical studies of console steel rod 200 × 22.25 × 3.78 mm in size were carried out.

scholarly journals Experimental and Numerical Investigation of Resonance Characteristics of Novel Pumping Element Driven by Two Piezoelectric Bimorphs

2019 ◽  
Vol 9 (6) ◽  
pp. 1234 ◽  
Author(s):  
Yu-Chih Lin ◽  
Yu-Hsi Huang ◽  
Kwen-Wei Chu
Keyword(s):  
Speckle Pattern ◽  
Laser Doppler Vibrometer ◽  
Impedance Analysis ◽  
Vibration Characteristics ◽  
Mode Shapes ◽  
Electronic Speckle Pattern Interferometry ◽  
Element Analysis ◽  
Visible Displacement ◽  
Piezoelectric Bimorphs ◽  
Phase Motion

This paper describes the vibration characteristics of a dual-bimorph piezoelectric pumping element under fluid–structure coupling. Unlike the single bimorph used in most previous studies, the proposed device comprises two piezoelectric bimorphs within an acrylic housing. Amplitude-fluctuation electronic speckle pattern interferometry (AF-ESPI) was used to examine the visible displacement fringes in order to elucidate the anti-phase as well as in-phase motions associated with vibration. Analysis was also conducted using impedance analysis and laser Doppler vibrometer (LDV) based on the measurement of point-wise displacement. The experimental results of resonant frequencies and the corresponding mode shapes are in good agreement with those obtained using finite element analysis. The gain of flow rate obtained by the anti-phase motion of the dual-bimorph pumping element is larger than both those obtained by in-phase motion and the single bimorph pumping element. This work greatly enhances our understanding of the vibration characteristics of piezoelectric pumping elements with two bimorphs, and provides a valuable reference for the further development of bionic pump designs.

Dynamic Characteristics and Finite Element Model Updating of Micromachined Torsion Structures

2013 ◽  
Vol 284-287 ◽  
pp. 1831-1835
Author(s):  
Wei Hsin Gau ◽  
Kun Nan Chen ◽  
Yunn Lin Hwang
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Finite Element Model ◽  
Model Updating ◽  
Speckle Pattern ◽  
Element Model ◽  
Mode Shapes ◽  
Electronic Speckle Pattern Interferometry ◽  
Finite Element Model Updating ◽  
Element Analysis

In this paper, two experimental techniques, Electronic Speckle Pattern Interferometry and Stroboscopic Interferometry, and two different finite element analysis packages are used to measure or to analyze the frequencies and mode shapes of a micromachined, cross-shaped torsion structure. Four sets of modal data are compared and shown having a significant discrepancy in their frequency values, although their mode shapes are quite consistent. Inconsistency in the frequency results due to erroneous inputs of geometrical and material parameters to the finite element analysis can be salvaged by applying the finite element model updating procedure. Two updating cases show that the optimization sequences converge quickly and significant improvements in frequency prediction are achieved. With the inclusion of the thickness parameter, the second case yields a maximum of under 0.4% in frequency difference, and all parameters attain more reliable updated values.

Damage Location Assessment in a Composite Panel by Means of Electronic Speckle Pattern Interferometry Measurements

2005 ◽  
Author(s):  
Alessandro Zanarini
Keyword(s):  
Structural Damage ◽  
Speckle Pattern ◽  
Harmonic Excitation ◽  
Speckle Interferometry ◽  
Composite Panel ◽  
Electronic Speckle Pattern Interferometry ◽  
Full Field ◽  
Damage Location ◽  
Displacement Maps ◽  
Non Destructive

The assessment of structural damage location in composite honeycomb sandwich panels is here pursued by means of a complete experimental non-destructive approach on a pre-damaged sample. In the experiments proposed full field displacement maps were acquired by means of optical non-contact Electronic Speckle Pattern Interferometry (ESPI) technology [1, 2], in order to obtain high spatial definition and locate small defects on the sample, like debondings, material separations, voids, cracks and delaminations. When dealing with holographic/speckle interferometry it is important to find the stressing technique able to produce singularities in the state of the object surface. Four different loading approaches were taken to detect the flaws: acoustic, thermal, static and harmonic excitation. The displacement maps acquired depict with high accuracy the inhomogeneous local behavior of the structure induced by the defects. Results are reported from the different loading approaches and discussed in detail.

Interpretation of Experimental and Theoretical Data for Prediction of Mode Shapes of Vibrating Turbocharger Blades

1988 ◽  
Vol 110 (1) ◽  
pp. 53-58 ◽  
Author(s):  
G. M. Chapman ◽  
X. Wang
Keyword(s):  
Natural Frequencies ◽  
Speckle Pattern ◽  
Theoretical Data ◽  
Mode Shapes ◽  
Electronic Speckle Pattern Interferometry ◽  
Experimental Investigations ◽  
Exhaust Gas ◽  
Element Analysis ◽  
Design Engineers ◽  
Vibration Excitation

The blading in large turbochargers is subjected to vibration excitation originating from pulsations in the exhaust gas stream coupled with the blade pass frequencies. The amplitude of vibrations induced are a source of concern to design engineers as they can seriously affect the operation of the turbocharger. This paper discusses theoretical and experimental investigations aimed at identifying the natural frequencies and the associated mode shapes for a single turbocharger blade. Modal Analysis, Electronic Speckle Pattern Interferometry (ESPI), and Finite Element Analysis are all used in an attempt to categorize the modal patterns.

scholarly journals Digital Double-Pulse Holographic Interferometry for Vibration Analysis

1996 ◽  
Vol 3 (2) ◽  
pp. 117-125
Author(s):  
H.J. Tiziani ◽  
G. Pedrini
Keyword(s):  
Holographic Interferometry ◽  
Vibration Analysis ◽  
Speckle Pattern ◽  
Ccd Camera ◽  
Image Plane ◽  
Speckle Interferometry ◽  
Electronic Speckle Pattern Interferometry ◽  
3 Dimensional ◽  
Digital Reconstruction ◽  
Fitting Method

Different arrangements for double-pulsed holographic and speckle interferometry for vibration analysis will be described. Experimental results obtained with films (classical holographic interferometry) and CCD cameras (digital holographic interferometry) as storage materials are presented. In digital holography, two separate holograms of an object under test are recorded within a few microseconds using a CCD camera and are stored in a frame grabber. The phases of the two reconstructed wave fields are calculated from the complex amplitudes. The deformation is obtained from the phase difference. In the case of electronic speckle pattern interferometry (or image plane hologram), the phase can be calculated by using the sinusoid-fitting method. In the case of digital holographic interferometry, the phase is obtained by digital reconstruction of the complex amplitudes of the wave fronts. Using three directions of illumination and one direction of observation, all the information necessary for the reconstruction of the 3-dimensional deformation vector can be recorded at the same time. Applications of the method for measuring rotating objects are discussed where a derotator needs to be used.

scholarly journals Investigation on Non-Linear Vibration Response of Cantilevered Thin Plates with Crack Using Electronic Speckle Pattern Interferometry

Proceedings ◽  
2018 ◽  
Vol 2 (8) ◽  
pp. 539
Author(s):  
Nan Tao ◽  
Yinhang Ma ◽  
Hanyang Jiang ◽  
Meiling Dai ◽  
Fujun Yang
Keyword(s):  
Mode Shape ◽  
Speckle Pattern ◽  
Experimental Studies ◽  
Forced Response ◽  
Thin Plates ◽  
Mode Shapes ◽  
Electronic Speckle Pattern Interferometry ◽  
Intact Specimen ◽  
Harmonic Resonance ◽  
Super Harmonic Resonance

The time-averaged electronic speckle pattern interferometry (ESPI) is employed to measure the frequencies and mode shapes of thin, cantilevered plates with root-slit. The first 12 order linear resonance frequency and mode shape of an intact cantilevered plate is determined by using FEM calculation. The dynamic response of the intact specimen forced by a PZT actuator is measured and its super-harmonic resonance of forced response is investigated experimentally. The results show that the principal mode shape of super-harmonic vibration is similar to its natural modal. In contrast to linear forcing vibration, the threshold of force for super-harmonic resonance is much higher than that of the former. In addition, linear free response of four cantilevered root-slit plates with variation length of slit are analyzed by applying the FEM calculation, and their responses of forcing vibration were measured by using the ESPI method. The validity and accuracy of the numerical prediction are confirmed through experimental studies. The present work shows that the ESPI technique can provide whole-field and real-time measurement for vibration analysis and can also be employed for validation of the FEM calculation.

Speckle Techniques for Noncontact Temperature Measurement

1994 ◽  
Vol 342 ◽  
Author(s):  
D. Burckel ◽  
S. H. Zaidi ◽  
M. K. Lang ◽  
A. Frauenglass ◽  
S. R. J. Brueck
Keyword(s):  
Temperature Measurement ◽  
Thermal Processing ◽  
Cross Correlation ◽  
Speckle Pattern ◽  
Speckle Interferometry ◽  
Back Surface ◽  
Electronic Speckle Pattern Interferometry ◽  
Correlation Technique ◽  
Full Field ◽  
Cross Correlation Technique

ABSTRACTTwo complementary speckle techniques for the measurement of temperature from the rough back surface of Si wafers during rapid thermal processing are demonstrated. Electronic speckle pattern interferometry is a full field intensity cross-correlation technique that provides a two-dimensional map of the surface temperature. Measurements are presented that demonstrate a resolution of ∼ ±2°C. A new speckle technique, sub-feature speckle interferometry is introduced. This technique provides a much more rapid and precise averaged temperature measurement by monitoring the strain between two points with interferometric precision usually associated with moird interferometry or holography rather than speckle. Preliminary measurements are presented that demonstrate the capability of the technique.

scholarly journals Electronic Speckle Pattern Interferometry for Vibrational Analysis of Cutting Tools

2018 ◽  
Vol 12 (2) ◽  
pp. 135-140
Author(s):  
Piotr Mrozek ◽  
Ewa Mrozek ◽  
Andrzej Werner
Keyword(s):  
Speckle Pattern ◽  
Laser System ◽  
Michelson Interferometer ◽  
Cutting Tools ◽  
Vibrational Analysis ◽  
Mode Shapes ◽  
Electronic Speckle Pattern Interferometry ◽  
Measurement Methodology ◽  
Fringe Patterns ◽  
Plane Displacement

Abstract A Michelson interferometer based ESPI system for static and vibration out of plane displacement measurements is presented. The aim of the article is to demonstrate the usability of ESPI non-contact measurement method in the field of machining. The correlation fringe patterns were visualized using custom software. The accuracy of ESPI interferometer was verified by the comparison with measurement results collected using industrial XL-80 laser system. The efficacy in vibration analysis was tested by studying the mode shapes and resonant frequencies of the transverse vibrations of square plates. The measurement methodology was used to determine natural frequencies and the shapes of vibrational modes of NFTe 100x1.2/64-II circular slitting saw. As a result the values of rotational speed that should be avoided during machining were determined.

A new Approach in Residual Stresses Analysis by Speckle Interferometry

2006 ◽  
Vol 524-525 ◽  
pp. 465-470 ◽  
Author(s):  
Afaf Maras ◽  
Guillaume Montay ◽  
Olivier Sicot ◽  
Emmanuelle Rouhaud ◽  
Manuel François
Keyword(s):  
Residual Stresses ◽  
Speckle Pattern ◽  
Speckle Interferometry ◽  
Electronic Speckle Pattern Interferometry ◽  
Stress Profile ◽  
Reliable Prediction ◽  
New Approach ◽  
Ultrasonic Shot Peening ◽  
Internal Stress Field ◽  
Fringe Patterns

The knowledge of residual stresses allows a reliable prediction of structure performances evolution, such as service life [1-3]. In this paper, we develop a new method for residual stresses determination combining Electronic Speckle Pattern Interferometry (ESPI) with the machining of a groove. The internal stress field is perturbed as the depth of the groove is increased incrementally. The structure finds a new equilibrium state generating displacements which are measured using ESPI. This method was tested on an aluminium alloy AU4G plate treated locally by an ultrasonic shot-peening. The investigation of the images obtained with the phase shifting technique and fringe patterns, makes it possible to analyze, simultaneously, the stress profile along two directions: along the depth of the structure, and along the groove direction.

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