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Residual Stress Measurement of an Interference Fit Specimen Based on Moiré Interferometry and Hole-Drilling Method
Issue:
Volume 4, Issue 3-1, June 2015
Pages:
1-4
Received:
16 February 2015
Accepted:
23 March 2015
Published:
12 May 2015
Abstract: In this paper, moiré interferometry is combined with hole-drilling method to measure the residual stress of an interference fit specimen. And, finite element method is used to calibrate the coefficient of hole-drilling method. The experimental results are consistent with theoretical results, which manifests that moiré interferometry combined with hole-drilling method are reliable and effective for residual stress measurement.
Abstract: In this paper, moiré interferometry is combined with hole-drilling method to measure the residual stress of an interference fit specimen. And, finite element method is used to calibrate the coefficient of hole-drilling method. The experimental results are consistent with theoretical results, which manifests that moiré interferometry combined with h...
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Fabrication of Micro-grating Structure by Nanosecond Laser
Yanlong Huang,
Jianguo Zhu
Issue:
Volume 4, Issue 3-1, June 2015
Pages:
5-8
Received:
23 February 2015
Accepted:
30 March 2015
Published:
12 May 2015
Abstract: The fabrication method by nanosecond laser technology for micro-grating is investigated in this paper. A nanosecond laser system is established and the mechanism of laser processing on material surface is theoretically analyzed. The damage threshold of stainless steel is obtained experimentally when the nanosecond laser irradiates on the specimen’s surface and the influence of the laser pulse energy to the fabricated micro-gratings are also studied. In the end, micro-gratings with high-quality are provided to validate the feasibility of the fabrication method by nanosecond laser technology.
Abstract: The fabrication method by nanosecond laser technology for micro-grating is investigated in this paper. A nanosecond laser system is established and the mechanism of laser processing on material surface is theoretically analyzed. The damage threshold of stainless steel is obtained experimentally when the nanosecond laser irradiates on the specimen’s...
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Full-Field Displacement Measurement Technique by Using Repeated Patterns and JPEG Compressed Images
Shien Ri,
Satoshi Hayashi,
Hiroshi Tsuda,
Shinji Ogihara
Issue:
Volume 4, Issue 3-1, June 2015
Pages:
9-13
Received:
27 March 2015
Accepted:
26 June 2015
Published:
6 July 2015
Abstract: This paper presents an experimental technique for measuring displacement distribution from an image of repeated patterns and JPEG compressed images. The measurement accuracy of the developed method is insusceptible to the degree of JPEG compression because only lower spatial frequency components of the repeated pattern are used to calculate the displacement distribution, and high spatial frequency components have high priority to cut-off according to the JPEG compression algorithm. The insensitivity to the JPEG compression was confirmed by a displacement measurement using JPEG images of various compression ratios or image qualities. We found that by using the highest quality JPEG image, the accuracy of displacement measurement could research 1/1000 of the repeated pattern pitch, as same the uncompressed BMP images. In addition, displacement with accuracy of 1/500 pitch could be measured from a compressed JPEG image of which the file size was 1/50 of that of the BMP image. This technique is useful for measurement using a high-speed camera with high-resolution digital images for a long-term or wireless image transfer.
Abstract: This paper presents an experimental technique for measuring displacement distribution from an image of repeated patterns and JPEG compressed images. The measurement accuracy of the developed method is insusceptible to the degree of JPEG compression because only lower spatial frequency components of the repeated pattern are used to calculate the dis...
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Measurement of Distortion Using the Moire Interferometry
K. Wenzel,
Gy. Abraham,
P. Tamas,
A. Urbin
Issue:
Volume 4, Issue 3-1, June 2015
Pages:
14-17
Received:
30 March 2015
Accepted:
12 July 2015
Published:
25 July 2015
Abstract: Image forming lens systemsdo not provide perfect images. Lens abberations can be detected with complex optical ray-tracing. A single aberration in lenses, the distortion, can be detected at the image plane with optical mapping. Therefore moiré interferometry can be adapted to detect and measure distortion. This method is adaptable by serial testing of the universal measuring cameras, projection cameras, photogrammetrical cameras, etc. The distortion of the whole image plane can be represented on one moiré image. This can be useful if the distortion is not rotationally symmetrical for example because of errors of assembly. The distortion of 1 µm regarding the focal plane can be measured by using the moiré method presented in this paper.
Abstract: Image forming lens systemsdo not provide perfect images. Lens abberations can be detected with complex optical ray-tracing. A single aberration in lenses, the distortion, can be detected at the image plane with optical mapping. Therefore moiré interferometry can be adapted to detect and measure distortion. This method is adaptable by serial testing...
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Calibration of a Fringe Projection 3D Measurement System Using an Equi-Phase Coordinate Method Based on Two-Reference-Plane
Dai Meiling,
Yang Fujun,
He Xiaoyuan
Issue:
Volume 4, Issue 3-1, June 2015
Pages:
18-23
Received:
23 March 2015
Accepted:
25 March 2015
Published:
28 July 2015
Abstract: Calibration is to transform the 2D phase information to the world coordinates in a fringe projection 3D measurement system. For the phase-to-height conversion, an equi-phase coordinate method based on two-reference-plane is proposed in this paper. The surface height is calculated by a linear interpolation using the coordinates where have the identical phase value of the object and the two reference planes. The conventional method, called equi-coordinate phase method in this paper, builds the function of the absolute phase and height by using the absolute phase obtained by subtracting the phase of object from that of the reference plane in the same coordinate. The proposed method can handle phase-to-height conversion and non-sinusoidal error caused by nonlinear response of the fringe projection system in one go. Theoretical and experimental analysis is given to prove the validity of the proposed method. Result indicates that the RMS error produced by equi-phase coordinate method is less half of equi-coordinate phase method when the primary error source is from the non-sinusoidal fringe patterns
Abstract: Calibration is to transform the 2D phase information to the world coordinates in a fringe projection 3D measurement system. For the phase-to-height conversion, an equi-phase coordinate method based on two-reference-plane is proposed in this paper. The surface height is calculated by a linear interpolation using the coordinates where have the identi...
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Virtually and Depth Sensor Generated Moire Pictures in Screening and Treatment of Scoliosis
Akos Antal,
Attila Katona,
Peter Major,
Jozsef Molnar,
Norbert Szakaly,
Peter Tamás,
Klara Wenzel
Issue:
Volume 4, Issue 3-1, June 2015
Pages:
24-28
Received:
30 March 2015
Accepted:
26 July 2015
Published:
7 August 2015
Abstract: In this paper, different moiré picture generation techniques are presented. This paper presents the basics of moiré effects, a virtual way of moiré generation, depth sensor based moiré picture generation and usage. One of the most common advantages of these methods is rapidity. The computer generated moiré pictures provide an opportunity of screening diagnosis. The depth sensor generated moiré fringes are precise and easy to process. A neural network based reconstruction of vertebral supports both the screening diagnosis and the treatment of scoliosis.
Abstract: In this paper, different moiré picture generation techniques are presented. This paper presents the basics of moiré effects, a virtual way of moiré generation, depth sensor based moiré picture generation and usage. One of the most common advantages of these methods is rapidity. The computer generated moiré pictures provide an opportunity of screeni...
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Residual Stress Measurement in Micro-region Using Digital Image Correlation Method
Issue:
Volume 4, Issue 3-1, June 2015
Pages:
29-32
Received:
29 March 2015
Accepted:
15 July 2015
Published:
2 September 2015
Abstract: The residual stress of the zirconia film on a stainless steel substrate is measured using the digital image correlation (DIC) method. A lattice structure is milled by focused ion beam (FIB) and used as the deformation carrier. An annular groove is etched by FIB in order to release the residual stress. The DIC method is used to calculate the deformation caused by the release of residual stress and the residual stress is derived by mechanics equations. The results demonstrate that this method can be extended for micro-region residual stress measurement of other thin films on substrates.
Abstract: The residual stress of the zirconia film on a stainless steel substrate is measured using the digital image correlation (DIC) method. A lattice structure is milled by focused ion beam (FIB) and used as the deformation carrier. An annular groove is etched by FIB in order to release the residual stress. The DIC method is used to calculate the deforma...
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Residual Stress Measurement in Si-based Multilayer Structure by Micro-Raman Spectroscopy
Wei Qiu,
CuiLi Cheng,
Yu Cheng Zhao,
Qiu Li
Issue:
Volume 4, Issue 3-1, June 2015
Pages:
33-38
Received:
20 March 2015
Accepted:
8 July 2015
Published:
29 November 2015
Abstract: Si-based multilayer structures, such as porous silicon (PS) and germanium silicon (ε-Si), are widely used in current microelectronics and Micro-electromechanical Systems (MEMS). During the preparing process of Si-based multilayer structures, some inhomogeneous residual stress is induced, maybe finally leading to structure failure. Micro-Raman Spectroscopy (MRS) is regarded as an effective method for intrinsic stress measurement. In this work, MRS is applied to analysis the residual stress distribution along the cross section of Si-based multilayer structure. Raman experimental results show that there are noticeable residual stress in both silicon substrate and the films (including porous silicon film and germanium-silicon buffer layers). The residual stress is linearly varied in most regions, which leads to an overall warp of the structure. While nonlinear variation of residual stress appears at the interface between different films and Si-substrate. Based on the experimental results, a spectra-mechanical model for analyzing the transversely-isotropic material like porous silicon was presented. A set of detailed Raman stress relationship of porous silicon was achieved. For the study of strained silicon wafer, the structural analyses by using high-resolution transmission electron microscope (HR-TEM) were cooperated with the residual stress measurement by Micro-Raman. And an analysis procedure of the residual stress evaluation on multilayer germanium silicon structures was introduced.
Abstract: Si-based multilayer structures, such as porous silicon (PS) and germanium silicon (ε-Si), are widely used in current microelectronics and Micro-electromechanical Systems (MEMS). During the preparing process of Si-based multilayer structures, some inhomogeneous residual stress is induced, maybe finally leading to structure failure. Micro-Ram...
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Fabrication of Micro-Scale Speckles with Particle Dispersion Method
He Guanglong,
Zhu Jianguo
Issue:
Volume 4, Issue 3-1, June 2015
Pages:
39-42
Received:
12 March 2015
Accepted:
8 June 2015
Published:
20 January 2016
Abstract: Micro-scale speckles with particle dispersion method are fabricated as the deformation carriers in the digital image correlation method. Micro-scale carbon particles are mixed with epoxy resin proportionally, followed by solidifying, centrifugal and spinning. In the end, a speckle film can be fabricated, which can be transferred to the surface of specimen. The quality of speckles is evaluated by the average gray gradient and the fabrication parameters including solidifying time, centrifuge speed, and spinning rate are studied and optimized.
Abstract: Micro-scale speckles with particle dispersion method are fabricated as the deformation carriers in the digital image correlation method. Micro-scale carbon particles are mixed with epoxy resin proportionally, followed by solidifying, centrifugal and spinning. In the end, a speckle film can be fabricated, which can be transferred to the surface of s...
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Deformation Measurement Method Using Moiré Fringes at High Scanning Speed Under a Laser Scanning Microscope
Qinghua Wang,
Shien Ri,
Hiroshi Tsuda,
Takashi Tokizaki
Issue:
Volume 4, Issue 3-1, June 2015
Pages:
43-49
Received:
31 March 2015
Accepted:
31 March 2015
Published:
14 March 2016
Abstract: A full-field deformation measurement method using moiré fringes generated at high scanning speed under a laser scanning microscope (LSM) was proposed. The formation principle and the deformation measurement principle were presented. Simulation and experiment verifications were performed to show the effectiveness and the accuracy of the proposed fast scanning moiré method, where the scanning line spacing is an integral multiple of the basic scanning line spacing. The moiré spacing, and the deformation measurement sensitivity and accuracy are almost the same as in the traditional LSM scanning moiré method. The fast scanning process allows a high scanning speed and a large view field without reducing the deformation measurement sensitivity. The higher measurement speed makes this method more suitable to be combined with the phase-shifting technique than the traditional LSM scanning moiré method. Besides, the application scope of the LSM moiré method in the field of deformation measurement is extended because more specimen gratings can be used to generate moiré fringes.
Abstract: A full-field deformation measurement method using moiré fringes generated at high scanning speed under a laser scanning microscope (LSM) was proposed. The formation principle and the deformation measurement principle were presented. Simulation and experiment verifications were performed to show the effectiveness and the accuracy of the proposed fas...
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