Dynamic Electronic Speckle Pattern Interferometry Research Articles

Dynamic ESPI Evaluation of Deformation and Fracture Mechanism of 7075 Aluminum Alloy.

The deformation and fracture mechanism in 7075 aluminum alloy is discussed based on a field theoretical approach. A pair of peak-aged and overaged plate specimens are prepared under the respective precipitation conditions, and their plastic deformation behaviors are visualized with two-dimensional electronic speckle pattern interferometry (ESPI). The in-plane velocity field caused by monotonic tensile loading is monitored continuously via the contour analysis method of ESPI. In the plastic regime, the peak-aged specimen exhibits a macroscopically uniform deformation behavior, while the annealed specimen exhibits non-uniform deformation characterized by a localized shear band. The occurrence of the shear band is explained by the transition of the material’s elastic resistive mechanism from the longitudinal force dominant to shear force dominant mode. The shear force is interpreted as the frictional force that drives mobile dislocations along the shear band. The dynamic behavior of the shear band is explained as representing the motion of a solitary wave. The observed decrease in the solitary wave’s velocity is accounted for by the change in the acoustic impedance with the advancement of plastic deformation.

Fully automated extraction of the fringe skeletons in dynamic electronic speckle pattern interferometry using a U-Net convolutional neural network

With the development of artificial intelligence technology, intelligent fringe processing is a goal of relevant researchers in optical interferometry. We propose an intelligent method to achieve fully automated extraction of the fringe skeletons in electronic speckle pattern interferometry (ESPI) based on U-Net convolutional neural network. In the proposed method, the network is first trained by the samples that consist of the noisy ESPI fringe patterns and the corresponding skeleton images. After training, the other multiframe ESPI fringe patterns are fed to the trained network simultaneously; the corresponding skeleton images can be obtained in batches. Using our method, it is not necessary to process fringe patterns frame by frame. Our method is especially suitable for multiframe fringe patterns processing. We apply the intelligent method to one computer-simulated and one real-dynamic ESPI measurement, respectively. For the simulated measurement, it takes just 40 s to obtain the skeleton images of 20 noisy ESPI fringe patterns using our method. Even for low-quality experimental obtained ESPI fringe patterns, our method can also give desired results.

Dynamic ESPI System for Spatio-Temporal Strain Analysis of a Deforming Solid Object

In Dynamic Electronic Speckle Pattern Interferometry (DESPI), deformation analysis could be done for successively acquired frame data of interfering speckle patterns with no additional frames like phase shifting speckle patterns. Our final goal is to obtain a temporally varying process of two-dimensional strain field. Two normal strains and shearing strain are derived by numerical derivatives of two components of in-plane deformation. Analyzed results of tensile experiments of an Al-alloy sample will be shown. In the experiments, propagation of a strain localization band accompanied by serration of a stress curve was clearly observed quantitatively analyzed.

Use of dynamic electronic speckle pattern interferometry with the Hilbert transform method to investigate thermal expansion of a joint material

A dynamic electronic speckle pattern interferometry method is applied to investigate thermal expansion of a joint material (ceramic-stainless steel) as a practical industrial object. The speckle interference signal is considered in the temporal domain and the phase is analyzed by the Hilbert transform method. Errors caused by the bias and modulation variations over the phase values are first examined by numerical simulation. Two experiments are performed with in-plane and out-of-plane sensitive systems to study the 3D deformation field thoroughly. The deformation field showed clearly the difference between the thermal expansions of the stainless steel and ceramic. It was also revealed that the boundary of materials and its vicinity suffer very large thermal strain due to the significantly large difference in the linear coefficient of thermal expansions.

Blooming Processes in Flowers Studied By Dynamic Electronic Speckle Pattern Interferometry (DESPI)

A dynamic electronic speckle pattern interferometry (ESPI) method was applied to study the blooming process in two kinds of flowers, the lily and the tulip. The complicated displacement fields of the flower petals were precisely monitored throughout the entire blooming process. The optical setup is a Fizeau type interferometer with relatively high robustness to air turbulence and vibrations. For quantitative evaluation of the displacement field, the subtraction-addition method (SAM), which utilizes only the digital signal processing of a sequence of images, was implemented. Measurements with accuracy in the range of λ/10 were achieved.

STATIC AND DYNAMIC CHARACTERIZATION OF MEMS VIA ESPI

International Journal of Computational Engineering ScienceVol. 04, No. 03, pp. 467-470 (2003) Testing and CharacterisationNo AccessSTATIC AND DYNAMIC CHARACTERIZATION OF MEMS VIA ESPIAndreas H. Foitzik, Wolfgang Kaese, Thomas Vogt, Michael Sommerer, and Serguei ArkhipovAndreas H. FoitzikUniversity of Applied Sciences Esslingen, Department for Mechatronics, Robert-Bosch-Str. 1, D-73037 Goeppingen, Germany Search for more papers by this author , Wolfgang KaeseUniversity of Applied Sciences Esslingen, Department for Mechatronics, Robert-Bosch-Str. 1, D-73037 Goeppingen, Germany Search for more papers by this author , Thomas VogtUniversity of Applied Sciences Esslingen, Department for Automotive Technology, Esslingen, Germany Search for more papers by this author , Michael SommererUniversity of Applied Sciences Esslingen, Department for Automotive Technology, Esslingen, Germany Search for more papers by this author , and Serguei ArkhipovMOSCOW AVIATION INSTITUTE (MAI), MOSCOW, Russia Search for more papers by this author https://doi.org/10.1142/S1465876303001538Cited by:2 PreviousNext AboutSectionsPDF/EPUB ToolsAdd to favoritesDownload CitationsTrack CitationsRecommend to Library ShareShare onFacebookTwitterLinked InRedditEmail AbstractGenerally unaltered surfaces stemming from IC- or MEMS-production (Micro Electro Mechanical Systems) cannot be investigated with ESPI (Electronic Speckle Pattern Interferometry) due to the lack of any interference from the extremely flat surfaces of devices made of silicon. In order to enable ESPI for such devices additional "rough" layers can be added to the MEMS surfaces, while these relatively "thick" layers alter the mechanical properties of such small devices considerably. Utilizing a new surface preparation technique (Goeppingen Procedure®) allows to create a nm-sized roughness onto the surfaces of MEMS, thus enabling interference originating from such altered surfaces and subsequently allowing ESPI.Static ESPI on commercially available micro-sized tilt-sensors as well as read-write head of a hard disk drive showed that elastic deformations can be determined with a lateral accuracy in the μm-range and an axial accuracy in the nm-range, respectively. The static investigations allowed the identification of defect sensors in terms of quality assurance. Dynamic ESPI on MEMS showed different normal modes as well as the dynamic behaviour at the occurence of the first and the second harmonic.Keywords:MEMSESPI - Electronic Speckle Pattern InterferometryGoeppingen Procedure References J. A. Leendertz, J. Phys. E (Sci. Instrum.) 3, 214 (1970). Crossref, Google Scholar H. Marwitz , Praxis Holographie ( Expert-Verlag , 1990 ) . Google ScholarP. Aswendt and R. Höfling, Measurement 23, S. 205 (1998). Crossref, Google ScholarD. Holsteinet al., Composite Structures 40, S. 257 (1998). Crossref, Google Scholar K. Hariri , Bruchmechanisches Verhalten jungen Betons: Laser-Speckle-Interferometrie und Modellierung der Rißprozeßzone ( Techn. Univ. Braunschweig , 2000 ) . Google ScholarZ. Yanget al., Optics and Lasers in Engineering 28(6), 443 (1997). Google Scholar Höfling, R.; Aswendt, P.; Liebig, V.; Brückner, H.: Synthesis of experiment and simulation in speckle interferometry: a medical application; Akademie Verlag Series in Optical Metrology, Vol. 2, S. 261-268, Berlin 1996 . Google Scholar Foitzik, A.H.; Kümmel, M.; Schmid, M.; Kaese, W.; Vogt, T.; Groth, P.; "ESPI on MEMS", 13.Intern. Wissenschaftlich-technische Konferenz SENSOR 2001, Sudak/Krim 2001 . Google Scholar FiguresReferencesRelatedDetailsCited By 2An Experimental Study of the Vibrational Characteristics of a Diamond Circular Blade Using Electronic Speckle-Pattern Interferometry and FEMMykhaylo Tkach, Yurii Halynkin, Arkadii Proskurin, Irina Zhuk and Volodymyr Kluchnyk et al.15 May 2021 | Acta Mechanica et Automatica, Vol. 15, No. 1Electronic Speckle Pattern Interferometry for Vibrational Analysis of Cutting ToolsPiotr Mrozek, Ewa Mrozek and Andrzej Werner17 July 2018 | Acta Mechanica et Automatica, Vol. 12, No. 2 Recommended Vol. 04, No. 03 Metrics History KeywordsMEMSESPI - Electronic Speckle Pattern InterferometryGoeppingen ProcedurePDF download

Study of free-convective onset on a horizontal wire using speckle pattern interferometry

The onset and development of heat convection from a suddenly heated thin horizontal wire in air has been studied experimentally by an optical technique, named dynamic electronic speckle pattern interferometry, which allows the acquisition of qualitative and quantitative data. Attention is focused in providing temperature field visualizations and data about the temporal behavior. The heat-rate-based Rayleigh number, Ra ∗ , ranges from 0.069 to 0.67, a region of parameters poorly covered by previous investigations. Experimental results are compared with previous data. The extent, at which existing correlations can be used for wires of 0.2 and 0.4 mm in diameter, is outlined. A new correlation is proposed.

Dynamic electronic speckle pattern interferometry (DESPI) phase analyses with temporal Hilbert transform

In this study, we propose the Hilbert transform (HT) method for phase analysis of a Dynamic ESPI signal. The data processing is performed in the temporal domain, using the temporal history of the interference signal at every single pixel. The final results give a temporal development of the two-dimensional deformation field. To reduce the influence of the fluctuations of bias intensity on the calculated phase, it was removed prior to performing the HT. This method was demonstrated for defects distinction and the determination of the sign change in the deformation field in two different experiments. The range of measurement lies between submicrons and tens of microns and the spatial resolution is better when compared to the fringe analysis method and the spatial carrier method.

Dynamic ESPI with subtraction–addition method for obtaining the phase

Dynamic electronic speckle pattern interferometry (DESPI) was developed for in situ observations. The quantitative evaluation of the deformation field was performed through 2-D subtraction–addition method (SAM) for phase analysis. This method does not require additional phase modulation, which makes it applicable to studying dynamic events. The method utilizes the ratio of the subtraction and addition correlation fringe patterns. The bias intensity that has to be removed from the addition images was determined by temporal averaging of a sequence of speckle patterns. To reduce the error, Gaussian filter was applied to the correlation fringe patterns. The deformation field was evaluated with accuracy of λ/10.

Extended-range temporal electronic speckle pattern interferometry.

In recent years the availability of high-speed digital video cameras has motivated the study of electronic speckle pattern interferometry (ESPI) in the time domain. To this end a properly sampled temporal sequence of N-fringe patterns is used to analyze the temporal experiment. Samples of temporal speckle images must fulfill the Nyquist criteria over the time axis. When the transient phenomena under study are too fast, the required sampling frequency over time may not be fulfilled. In that case one needs to extend the measuring range of the algorithm used to extract the modulating phase. We analyze how to use short laser pulses or short video acquisition times with fairly long temporal separation among them to estimate the modulating phase of a dynamic ESPI experiment. The only requirement is that the modulating phase being estimated be properly sampled in the spatial domain.

415 DESPI によるアルミ合金の塑性変形過程における PLC 効果の動的全視野計測

Electronic Speckle Pattern Interferometry (ESPI) has been developed to make possible to observe dynamic feature of deformation in Dynamic ESPI (DESPI). Precise phase analysis of "subtraction and addition method (SAM) is presented. Plastic deformation process of aluminum alloy (A2017) was analyzed. We found that there are two different features of the plastic deformation process. In the former process, plastic deformation is accompanied by vibration caused by strong energy concentration and relaxation. In the later process, switching between two quasi-stable states was observed frequently. These phenomena will be interpreted by Physical Mesomechanics (PMM)

Phase errors in low-frequency vibration measurement with high-speed phase-shifting speckle pattern interferometry

When mechanical vibrations are measured by means of a dynamic phase-shifting speckle pattern interferometer, the deformation can be tracked with an error that depends on the amplitude and frequency of the vibration. We use a numerical simulation based on a detailed mathematical model of the system to predict the expected frequency response of the root mean square (rms) measurement error in the time-varying phase difference maps. The performance of four phase- shifting algorithms (three-frame, four-frame, Carre, and Schwider- Hariharan five-frame) and a temporal phase unwrapping method is studied over a range of vibrational amplitudes and frequencies. The numerical results indicate that the Carre algorithm is the preferred phase-shifting method to measure vibrations with a dynamic electronic speckle pattern interferometry (ESPI) system. Vibration frequencies up to 30% of the carrier frequency can be measured with an rms phase change error less than l0% of the vibration amplitude. The numerical results are finally compared with experimental data, acquired using a 1000 frame/s phase-shifting speckle interferometer together with a laser vibrometer, which provides a reference phase measure.