Thermal strain analysis of composite materials by electronic speckle pattern interferometry

2000 ◽  
Vol 14 (5) ◽  
pp. 477-482 ◽  
Author(s):  
Koung Suk Kim ◽  
Wan Shik Jang ◽  
Myung Seak Hong ◽  
Ki Soo Kang ◽  
Hyun Chul Jung ◽  
...  
Keyword(s):  
Composite Materials ◽  
Speckle Pattern ◽  
Thermal Strain ◽  
Strain Analysis ◽  
Electronic Speckle Pattern Interferometry

Mapping of Surface Residual Stress Field by Laser Interferometry Using Stress Relaxation Method

2002 ◽  
Vol 750 ◽  
Author(s):  
Dong-Won Kim ◽  
Nak-Kyu Lee ◽  
Kyung-Hoan Na ◽  
Dongil Kwon
Keyword(s):  
Residual Stress ◽  
Stress Field ◽  
Speckle Pattern ◽  
Thermal Strain ◽  
Laser Interferometry ◽  
Relaxation Method ◽  
Electronic Speckle Pattern Interferometry ◽  
Residual Stress Field ◽  
Surface Residual Stress ◽  
Au Film

ABSTRACTBased on the identification of the residual stress-free state using electronic speckle pattern interferometry (ESPI), we modeled the relaxed stress in annealing, the thermal strain/stress and the residual stress field in case of both single and film/substrate systems by using the thermo-elastic theory and the relationship between relaxed stresses and displacements. Thus we mapped the surface residual stress fields on the indented bulk Cu and the 0.5μm Au film by ESPI. In indented Cu, the normal and shear residual stress are distributed over -800 MPa to 700 MPa and -600 MPa to 600 MPa respectively around the indented point and in deposited Au film on Si wafer, the tensile residual stress is uniformly distributed on the Au film from 500 MPa to 800 MPa. Also we measured the residual stress by the x-ray diffractometer (XRD) for the verification of above residual stress results by ESPI.

A Study on the Vibration Characteristics of Symmetry and Asymmetry Laminated Composite Materials by Using ESPI

2007 ◽  
Vol 353-358 ◽  
pp. 2366-2370
Author(s):  
Kyung Min Hong ◽  
Young June Kang ◽  
Nak Kyu Park ◽  
Weon Jae Ryu
Keyword(s):  
Composite Materials ◽  
Real Time ◽  
Optical Measurement ◽  
Speckle Pattern ◽  
Laminated Composite ◽  
Vibration Characteristics ◽  
Electronic Speckle Pattern Interferometry ◽  
Full Field ◽  
Reinforced Plastics ◽  
Laminated Composite Materials

The ESPI (Electronic Speckle Pattern Interferometry) is a real-time, full-field, non-destructive optical measurement technique. In this study, ESPI was proposed for the purpose of vibration analysis for new and composite materials. Composite materials have various complicated characteristics according to the materials, orientations, stacking sequences of the ply and boundary conditions. Therefore, it was difficult to analyze composite materials. For efficient use of composite materials in engineering applications the dynamic behavior (i.e., natural frequencies and nodal patterns) should be informed. With the use of Time-Average ESPI, one could analyze vibration characteristics of composite material by real time easily. We manufactured two kinds of laminated composites (i.e., symmetry and asymmetry) which were consisted of CFRP (Carbon Fiber Reinforced Plastics) and the shape of the test piece was of rectangular form.

Double wavelength combined electronic speckle pattern interferometry–moiré system for full-field strain analysis on electronic components

2018 ◽  
Vol 53 (6) ◽  
pp. 379-388
Author(s):  
Caterina Casavola ◽  
Giovanni Pappalettera
Keyword(s):  
Speckle Pattern ◽  
Strain Analysis ◽  
Thermal Dissipation ◽  
Electronic Speckle Pattern Interferometry ◽  
Systematic Bias ◽  
Electronic Components ◽  
Displacement Fields ◽  
Field Methods ◽  
Full Field ◽  
Set Up

Determination of thermal dissipation capability and thermomechanical behavior of electronic components is becoming a relevant topic in view of the fact that thermal management can strongly affect reliability and lifetime of the component. The level of miniaturization, which is achieved in current electronics, requires that no-contact analysis must be privileged in view of the fact that any contact with the chip can significantly alter the heat capacity of the component and to introduce a systematic bias in the measurements. Moreover, the high complexity of electronics components suggests that full-field methods should be adopted in order to take into account about differences in terms of thermomechanical response in different areas of the same sample. In this article, an original optical set-up including a speckle interferometer and a projection moiré branch was developed; this system comprises two different laser sources emitting at two different wavelengths. Recording by a color camera allows detecting simultaneously the speckle pattern and the projected fringes. The whole information is successively separated in the post-processing stage and this allows obtaining in-plane and out-of-plane displacement fields. The system demonstrated its capability to determine dynamic response of the LM1084 analyzed component and, moreover, to detect the presence of a functional damage.

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

2006 ◽  
Vol 326-328 ◽  
pp. 95-98 ◽  
Author(s):  
Tomohisa Shiraishi ◽  
Satoru Toyooka ◽  
Hirofumi Kadono ◽  
Takayuki Saito ◽  
Sun Ping
Keyword(s):  
Speckle Pattern ◽  
Plane Deformation ◽  
Strain Analysis ◽  
Electronic Speckle Pattern Interferometry ◽  
Deformation Analysis ◽  
Al Alloy ◽  
Alloy Sample ◽  
Speckle Patterns ◽  
Stress Curve ◽  
Spatio Temporal

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.

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