Tire Experimental Characterization Using Contactless Measurement Methods

2021 ◽  
Keyword(s):  
Combustion Engine ◽  
Measurement Techniques ◽  
Laser Doppler Vibrometer ◽  
Operating Conditions ◽  
Image Correlation ◽  
Optical Methods ◽  
Mode Shapes ◽  
Contactless Measurement ◽  
Full Field ◽  
Static Conditions

In the frame of automotive Noise Vibration and Harshness (NVH) evaluation, inner cabin noise is among the most important indicators. The main noise contributors can be identified in engine, suspensions, tires, powertrain, brake system, etc. With the advent of E-vehicles and the consequent absence of the Internal Combustion Engine (ICE), tire/road noise has gained more importance, particularly at mid-speed driving and in the spectrum up to 300 Hz. At the state of the art, the identification and characterization of Noise and Vibration sources rely on pointwise sensors (microphones, accelerometers, strain gauges). Optical methods such as Digital Image Correlation (DIC) and Laser Doppler Vibrometer (LDV) have recently received special attention in the NVH field because they can be used to obtain full-field measurements. Moreover, these same techniques could also allow to characterize the tire behavior in operating conditions, which would be practically impossible to derive with standard techniques. In this paper we will demonstrate how non-contact full-field measurement techniques can be used to reliably and robustly characterize the tire behavior up to 300 Hz, focusing on static conditions. Experimental modal analysis will extract the modal characteristic of the tire in both free-free and statically preloaded boundary conditions, using both DIC and LDV. The extracted natural frequencies, damping ratios and full-field mode shapes will be used on one side to improve the accuracy of tire models (either by deriving FRF based models or updating FE ones) but also as a reference for future investigation on the tire behavior characterization in rotating conditions.

Application of High Speed Image Correlation for Measurement of Mode Shapes of a Car Bonnet

2011 ◽  
Vol 70 ◽  
pp. 45-50
Author(s):  
Thorsten Siebert ◽  
Wei Zhuo Wang ◽  
John E. Mottershead ◽  
Andrea Pipino
Keyword(s):  
High Speed ◽  
Speckle Pattern ◽  
Measurement Techniques ◽  
Image Correlation ◽  
Mode Shapes ◽  
Analysis Tool ◽  
Full Field ◽  
Digital Speckle Pattern Interferometry ◽  
Full Field Measurement ◽  
Wide Range

For the analysis of vibrations and mode shape extraction in particular the use of optical full-field measurement techniques has grown during the last years. Beside techniques like Digital Speckle Pattern Interferometry, Moiré, Thermography or Photoelasticity the Digital Image Correlation techniques have already been successfully proven to be an accurate displacement analysis tool for a wide range of applications.

scholarly journals Stereo-DIC Measurements of a Vibrating Bladed Disk: In-Depth Analysis of Full-Field Deformed Shapes

2021 ◽  
Vol 11 (12) ◽  
pp. 5430
Author(s):  
Paolo Neri ◽  
Alessandro Paoli ◽  
Ciro Santus
Keyword(s):  
Single Point ◽  
Excitation Frequency ◽  
Phase Variation ◽  
Operating Conditions ◽  
Image Correlation ◽  
Response Analysis ◽  
Full Field ◽  
Low Speed ◽  
Bladed Disk ◽  
Depth Analysis

Vibration measurements of turbomachinery components are of utmost importance to characterize the dynamic behavior of rotating machines, thus preventing undesired operating conditions. Local techniques such as strain gauges or laser Doppler vibrometers are usually adopted to collect vibration data. However, these approaches provide single-point and generally 1D measurements. The present work proposes an optical technique, which uses two low-speed cameras, a multimedia projector, and three-dimensional digital image correlation (3D-DIC) to provide full-field measurements of a bladed disk undergoing harmonic response analysis (i.e., pure sinusoidal excitation) in the kHz range. The proposed approach exploits a downsampling strategy to overcome the limitations introduced by low-speed cameras. The developed experimental setup was used to measure the response of a bladed disk subjected to an excitation frequency above 6 kHz, providing a deep insight in the deformed shapes, in terms of amplitude and phase distributions, which could not be feasible with single-point sensors. Results demonstrated the system’s effectiveness in measuring amplitudes of few microns, also evidencing blade mistuning effects. A deeper insight into the deformed shape analysis was provided by considering the phase maps on the entire blisk geometry, and phase variation lines were observed on the blades for high excitation frequency.

The Use of Modan 3D in Experimental Modal Analysis

2013 ◽  
Vol 486 ◽  
pp. 36-41 ◽  
Author(s):  
Róbert Huňady ◽  
František Trebuňa ◽  
Martin Hagara ◽  
Martin Schrötter
Keyword(s):  
Modal Analysis ◽  
Vibration Analysis ◽  
High Speed ◽  
Mechanical Vibration ◽  
Steel Sample ◽  
Experimental Modal Analysis ◽  
Image Correlation ◽  
Optical Methods ◽  
Mode Shapes ◽  
Vibration Modes

Experimental modal analysis is a relatively young part of dynamics, which deals with the vibration modes identification of machines or their parts. Its development has started since the beginning of the eighties, when the computers hardware equipment has improved and the fast Fourier transform (FFT) could be used for the results determination. Nowadays it provides an uncountable set of vibration analysis possibilities starting with conventional contact transducers of acceleration and ending with modern noncontact optical methods. In this contribution we mention the use of high-speed digital image correlation by experimental determination of mode shapes and modal frequencies. The aim of our work is to create a program application called Modan 3D enabling the performing of experimental modal analysis and operational modal analysis. In this paper the experimental modal analysis of a thin steel sample performed with Q-450 Dantec Dynamics is described. In Modan 3D the experiment data were processed and the vibration modes were determined. The reached results were verified by PULSE modulus specialized for mechanical vibration analysis.

Investigating the Flexural Behaviour of Foams at High Strain Rate Using Optical Measurement Techniques

2013 ◽  
Vol 569-570 ◽  
pp. 799-804
Author(s):  
Duncan A. Crump ◽  
Janice M. Dulieu-Barton
Keyword(s):  
High Speed ◽  
Optical Measurement ◽  
Measurement Techniques ◽  
Maximum Load ◽  
Image Correlation ◽  
Test Machine ◽  
Full Field ◽  
Closed Cell ◽  
Load To Failure ◽  
Point Bend

Polymer closed cell foam beam specimens manufactured from H100 Divinycell (Diab) are tested in four point bend at three loading speeds using a specially designed rig and an Instron VHS test machine. Synchronised high speed images are captured using white light and infra-red thermography (IRT) to obtain the mid-point full-field deflection and strains using digital image correlation (DIC) along with the temperature evolutions. There is a marked increase in the maximum load to failure with loading rate and the optical techniques provide an opportunity to analyse the strain and temperature evolution within the specimens.

Shear Test on CFRP Full-Field Measurement and Finite Element Analysis

2010 ◽  
Vol 112 ◽  
pp. 49-62 ◽  
Author(s):  
Sébastien Mistou ◽  
Marina Fazzini ◽  
Moussa Karama
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Shear Modulus ◽  
Shear Test ◽  
Image Correlation ◽  
Optical Methods ◽  
Strain Gauges ◽  
Element Analysis ◽  
Full Field ◽  
Full Field Measurement

The purpose of this work is to study the Iosipescu shear test and more precisely its ability to characterize the shear modulus of a carbone/epoxy composite material. The parameters influencing this identification are the fibre orientation, the geometry of the notch and the boundary conditions. Initially these parameters were studied through the finite element analysis of the shear test. Then, the measurement of the shear strains was carried out by traditional methods of measurement (strain gauges) but also by optical methods. These optical methods: the digital image correlation and the electronic speckle pattern interferometry (ESPI); allow for various levels of loading, to reach a full-field measurement of the shear strain. This enabled us to study the strain distribution on the section between the two notches. The finite element model enabled us to study the parameters influencing the calculation of the shear modulus in comparison with strain gauges, image correlation and ESPI. This work makes it possible to conclude on optimal parameters for the Iosipescu test.

Application of Image Based Methods for Monitoring and Measurements of Structures in Power Stations

2012 ◽  
Vol 518 ◽  
pp. 24-36 ◽  
Author(s):  
Małgorzata Kujawińska ◽  
Marcin Malesa ◽  
Krzysztof Malowany ◽  
Paweł M. Błaszczyk
Keyword(s):  
Power Plants ◽  
Optical Measurement ◽  
Image Correlation ◽  
Optical Methods ◽  
Future Application ◽  
Monitoring And Control ◽  
Full Field ◽  
Advantages And Disadvantages ◽  
Power Stations ◽  
Steam Pipes

The implementation of selected full-field optical methods for monitoring and measurements of displacements, strains and shape of structures in power plants are reported. Digital Image Correlation, Fringe Projection and integrated thermovision-DIC method have been utilized for monitoring and control of repair processes of selected elements during general overhauls in power plants, including control of welds annealing process in boiler drum and steam pipes and measurements of geometry changes of steam pipes in “hot” and “cold” states. The experience gathered during the measurement sessions in power plants has been used for enhancement and adaptation of typical architecture of measurement systems to demanding and difficult industrial environment conditions. The measurements had been carried out in different power plants located in Poland. The possible future application of full-field optical measurement methods as the alternative to standard techniques (ultrasound, X-ray, strain gauges) and their advantages and disadvantages are discussed.

Optical Methods for Studies of Self-Excited Oscillations and the Effect of Dampers in a High Pressure Single Sector Combustor

2015 ◽  
Vol 137 (7) ◽  
Author(s):  
U. Meier ◽  
L. Lange ◽  
J. Heinze ◽  
C. Hassa ◽  
S. Sadig ◽  
...  
Keyword(s):  
High Pressure ◽  
Heat Release ◽  
Optical Measurement ◽  
Measurement Techniques ◽  
Operating Conditions ◽  
Optical Methods ◽  
Pressure Oscillations ◽  
Lean Burn ◽  
Reaction Zones ◽  
Injector Flows

Self-excited periodic instabilities in a staged lean burn injector could be forced by operating the combustor at off-design conditions. These pressure oscillations were studied in a high pressure single sector combustor with optical access. Two damper configurations were installed and tested with respect to their damping efficiency in relation to the configuration without dampers. For a variety of test conditions, derived from a part load case, time traces of pressure in the combustor were measured, and amplitudes were derived from their Fourier transformation. These measurements were performed for several combinations of the operating parameters, i.e., injector pressure drop, air/fuel ratio (AFR), pilot/main fuel split, and preheat temperature. These tests “ranked” the respective damper configurations and their individual efficiency with respect to the configuration without dampers. Although a general trend could be observed, the ranking was not strictly consistent for all operating conditions. For several test cases, preferably with pronounced self-excited pressure oscillations, phase-resolved planar optical measurement techniques were applied to investigate the change of spatial structures of fuel, reaction zones, and temperature distributions over a period of an oscillation. A pulsating motion was detected for both pilot and main flame, driven by a pulsating transport of the liquid fuel. This pulsation, in turn, is caused by a fluctuating air velocity, in connection with a prefilming airblast type atomizer. A phase shift between pilot and main injector heat release was observed, corresponding to a shift of fuel penetration. Local Rayleigh indices were calculated qualitatively, based on phase-resolved OH chemiluminescence used as marker for heat release, and corresponding pressure values. This identified regions, where a local amplification of pressure oscillations occurred. These regions were largely identical to the reaction regions of pilot and main injector, whereas the recirculation zone between the injector flows was found to exhibit a damping effect.

Image Analysis for Full-Field Displacement/Strain Data: Method and Applications

2011 ◽  
Vol 70 ◽  
pp. 39-44 ◽  
Author(s):  
Wei Zhuo Wang ◽  
John E. Mottershead ◽  
Christopher M Sebastian ◽  
Eann A Patterson ◽  
Thorsten Siebert ◽  
...  
Keyword(s):  
Image Analysis ◽  
Image Features ◽  
Kernel Functions ◽  
Orthogonal Basis ◽  
Image Correlation ◽  
Mode Shapes ◽  
Essential Information ◽  
Full Field ◽  
Field Displacement ◽  
Strain Data

Recent advances in measurement techniques, including digital image correlation, automated photoelasticity, electronic speckle pattern interferometry and thermoelastic stress analysis, permit full-field maps of displacement or strain to be obtained easily. They provide large volumes of mostly redundant data, which should be condensed to the essential information to permit straightforward processes such as validations of computational models or damage assessments. A way to do this is by image processing, an important aspect of which is the definition of an orthogonal basis (orthogonal kernel functions). Generally, this is problem dependent and requires some skill from the analyst if the number of image features (the coefficients of the orthogonal basis) is to be restricted to a suitably small number. Advantage may be taken of patterns of symmetry, for example cyclically symmetric patterns are well-suited to treatment by Zernike polynomials and rectangular patterns are well-suited to treatment by Fourier series. The Zernike and Fourier kernels are continuous polynomials with orthogonality properties that require integration and must be discretised. The discrete Tchebichef polynomials are ideal for the treatment of full-field information at multiple discrete data points. In many cases the data field is localised around a particular feature, such as local strain around a hole in a tension-test specimen. In this case, the polynomial basis should similarly be localised by various forms of scaling – this requires the application of the Gram-Schmidt procedure to maintain orthogonality. The image features (sometimes called shape features) are meaningful and may be used to identify particular patterns in the data – e.g. for detecting cracks or other forms of damage. When assembled in a feature vector, the distance between feature vectors from measured and numerical results are useful for refining numerical models. In this paper the principles of image analysis, as applied to full-field displacement/strain data are explained and experimental examples are used to illustrate the practical usefulness of the method. The applications include (i) vibration mode shapes of laminated honeycomb structures and, (ii) strain in an aluminium plate with a central hole in tension.

scholarly journals R-curve evaluation of pipeline girth welds using advanced measurement techniques

2014 ◽  
Vol 5 (1) ◽  
pp. 10
Author(s):  
Nick Geldhof ◽  
Joeri Van Iseghem ◽  
Matthias Verstraete ◽  
Stijn Hertelé ◽  
Koen Van Minnebruggen ◽  
...  
Keyword(s):  
Crack Extension ◽  
Measurement Techniques ◽  
Potential Drop ◽  
Image Correlation ◽  
Assessment Procedure ◽  
Full Field ◽  
Resistance Curves ◽  
Unloading Compliance ◽  
Girth Welds ◽  
Tearing Resistance

A strain-based flaw assessment procedure is recommended for girth welded pipelines subjected to large deformations. To evaluate the allowable defect dimensions, the tearing resistance needs to be characterized. This paper investigates the effect of weld metal strength mismatch on the resistance curve using Single Edge Notched Tension (SENT) specimens. Several advanced measurement techniques are applied during the tests in order to obtain a continuous measurement of crack extension and to visualize the deformation fields near the crack. The resistance curves are determined using a single specimen technique. The unloading compliance method and the potential drop method result in similar predictions of ductile crack extension, yielding similar resistance curves. Next to these measurements, the full field deformations are determined using digital image correlation. The experiments indicate that the position of the applied notch in the weld has the potential to influence the strain fields.

Rapid, Wide-Field Measurements of Complex Transient Shell Vibrations

2001 ◽  
Vol 123 (4) ◽  
pp. 537-543 ◽  
Author(s):  
Roman W. Motriuk ◽  
Timothy Schmidt
Keyword(s):  
Pressure Vessel ◽  
Measurement Techniques ◽  
Field Measurements ◽  
Operating Conditions ◽  
Dynamic Responses ◽  
Mode Shapes ◽  
Wide Field ◽  
Laboratory Measurements ◽  
Worst Case ◽  
Dynamic Strains

The mapping and evaluation of complex vibrational fields is often highly desirable in the pressure vessel and piping industry. It is also tedious and expensive using conventional technology such as strain gage and accelerometer arrays. This paper describes field and laboratory measurements made with a portable pulsed laser system that instantaneously captures displacement data over areas up to 2 m2, with submicron sensitivity. The results indicate that pulsed holographic or electronic speckle interferometry facilitates the evaluation of nonstationary vibrational fields with significant advantages over conventional techniques. Pulsed interferometry is an effective tool for rapidly determining locations of worst-case dynamic displacements and strains. Initial field measurements at a natural gas pumping station provided an exciting glimpse at both the measurement capability of the pulsed interferometry system and never before seen dynamic responses of turbo-compressor discharge piping. The piping immediate to the compressor discharge nozzle as well as a recycle pipe was investigated at a range of operating conditions. Several characteristic patterns were observed in the instantaneous operating deflection shapes. Most notable were spiral waves progressing both clockwise and counterclockwise relative to the axial flow direction. A “shock,” sudden drop in deformation, presumably caused by instantaneous back pressure, was also captured during an extensive statistical survey. Subsequently, laboratory measurements were made on a pressure vessel built to ASME Code requirements, with various internal fluid and pressure conditions. During shaker excitation, dynamic strains logged from gage rosettes were compared to captured displacements and mode shapes. Interestingly, the ratio of circumferential to axial dynamic strains was found to depend on the operating deflection shape of the vessel. Long, thin antinodes resulted in strain ratios expected for static loading, but short antinodes typical of higher frequency responses were accompanied by significantly increased axial strains. The authors intend to continue investigating the usefulness of pulsed interferometry measurements for the oil and gas industry. It is considered important to further correlate the interferometry measurements with traditional modal analysis and strain measurement techniques. Follow-up efforts will also attempt to quantify the relationship between wide-area vibrations and noise emanation from piping systems. An additional goal is to increase the efficiency of noise abatement solutions using insight obtained from wide-field vibration measurements.

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