Polarized shearing-moire interferometry for separated 3-D strain fringe patterns

1990 ◽  
Vol 6 (3) ◽  
pp. 281-288 ◽  
Author(s):  
Fang Jing ◽  
Dai Fulong
Keyword(s):  
Moiré Interferometry ◽  
Moire Interferometry ◽  
Fringe Patterns

Real-Time Monitoring and Simulation of Thermal Deformation in Plastic Package

1998 ◽  
Vol 120 (2) ◽  
pp. 160-165 ◽  
Author(s):  
J. Zhu ◽  
D. Zou ◽  
S. Liu
Keyword(s):  
Finite Element ◽  
Thermal Cycling ◽  
Real Time ◽  
Electronic Packaging ◽  
Thermal Deformation ◽  
Moiré Interferometry ◽  
Moire Interferometry ◽  
Plastic Package ◽  
Highly Nonlinear ◽  
Fringe Patterns

Thermally-induced failure is a major reliability issue for electronic packaging. Due to the highly nonlinear behaviors and thermal mismatch of packaging materials, an electronic package exhibits uneven thermal deformation in the whole temperature range during thermal cycling. This behavior will affect the buildup of thermal strain/stress within the package, which may affect the reliability of the package. Therefore, a real-time method is needed to monitor the thermal deformation of packages during the thermal cycling. In this study, a real-time moire´ interferometry technique coupled with a thermal vacuum chamber is used to monitor the thermal deformation of a plastic package. A grating is transferred onto the cross section of the sample at room temperature. The fringe patterns are recorded by a CCD camera system and are compared with the displacement contours obtained by nonlinear finite element simulation. High temperature moire´ results up to 200°C are reported here. The comparison between the moire´ fringe patterns and finite element results shows a good agreement. The results also show that the real-time moire´ interferometry technique is an effective way to monitor the thermal deformation of electronic packaging and is a powerful validation method for finite element analysis.

scholarly journals Moiré interferometry applied to fracture in titanium tubes

2007 ◽  
Vol 221 (3) ◽  
pp. 131-141
Author(s):  
P M MacKenzie
Keyword(s):  
Moiré Interferometry ◽  
Moire Interferometry ◽  
Tube Material ◽  
Optical Efficiency ◽  
Materials Research ◽  
Fringe Patterns ◽  
Plane Displacement ◽  
Crack Tip Opening ◽  
Exchanger Tube ◽  
Substantial Degree

Despite there being a substantial body of evidence to the contrary, moiré interferometry is often regarded - even by some adherents - as a curiosity of the optics lab. The present work seeks to demonstrate still further that the method can be an effective tool for practical materials research and assessment, in this case, in a novel and challenging experimental application involving fracture testing of heat exchanger tube material, the work being conducted in a conventional materials test laboratory setting. The key to the utility of the present setup lies with the priority given to its optical efficiency. In standard fracture toughness tests, it is axiomatic that standard specimen geometries be used. A dilemma arises when a material's properties are transformed to a substantial degree by the final stages of its process of manufacture, and when the very nature of the finished form dictates that standard geometries cannot be produced. The focus of this investigation was to measure crack-tip opening displacements (CTODs) in thin-walled titanium tubes. Fringe patterns corresponding to in-plane displacement contours were obtained interferometrically and the method for extracting CTODs from these is described. Significant differences in yield, ultimate strength, elongation, and fracture behaviour were observed for different material orientations.

Study of Residual Stress Distribution by a Combined Method of Moire´ Interferometry and Incremental Hole Drilling, Part II: Implementation

1998 ◽  
Vol 65 (4) ◽  
pp. 844-850 ◽  
Author(s):  
Zhu Wu ◽  
Jian Lu ◽  
Bongtae Han
Keyword(s):  
Residual Stress ◽  
Residual Stresses ◽  
Moiré Interferometry ◽  
Hole Drilling ◽  
Moire Interferometry ◽  
Combined Method ◽  
Incremental Hole Drilling ◽  
Experimental Apparatus ◽  
Fringe Patterns ◽  
Incremental Step

An experiment is devised to implement the combined method of moire´ interferometry and incremental hole drilling which was proposed in the companion paper. A unique experimental apparatus is designed to combine an optical set up for moire´ interferometry with an incremental hole-drilling device. The apparatus maintains a constant relative position of a drilling device to the specimen while alternating moire´ interferometry measurements with incremental hole drilling. The drill-bit can reenter the hole for each incremental step. The incremental hole-drilling device produces a precise control of incremental hole depth with an accuracy of 0.1 μm. The method is utilized to measure the residual stresses of two shot-peened materials: AS10U3NG aluminum alloy and the ten percent SiCp reinforced aluminum composite-F3K10S Duralcan with a T6 heat treatment. Moire´ fringe patterns with excellent contrast and high signal-to-noise ratio are obtained, which allows the extraction displacement data at the points very close to a hole boundary. In the experiment, a total number of ten steps of incremental hole drilling with an identical increment of 0.1 mm are performed. The fringe patterns of Ux and Uy displacement fields are recorded after each increment and the displacement data at the points of r = 1.2r0 are extracted consequently. They are used to determine the nonuniform residual stress distributions of surface and subsurface layers of shot-peened materials. The results indicate that the medium level of approximately equibiaxial compressive residual stresses exist within a 0.3 mm layer.

Heterodyne moiré interferometry for automated strain measurement

1994 ◽  
Vol 29 (2) ◽  
pp. 129-135 ◽  
Author(s):  
P M MacKenzie ◽  
C A Walker ◽  
J McKelvie ◽  
A McDonach
Keyword(s):  
Strain Measurement ◽  
Single Point ◽  
Strain Tensor ◽  
Moiré Interferometry ◽  
Moire Interferometry ◽  
Time Analysis ◽  
Real Time Analysis ◽  
Electro Optic ◽  
Heterodyne Technique ◽  
Fringe Patterns

Moiré interferometry is increasingly being applied to investigations in experimental mechanics. The present work seeks to address the problem of automated ‘real-time’ analysis of interferometric Moiré fringe patterns to obtain strain values. To this end, a portabe system is constructed to demonstrate the use of an electro-optic heterodyne technique on a single point, single component of strain basis. The prospect of expanding the setup to enable whole-field strain tensor evaluation is also discussed.

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