scholarly journals Non-Contact Measurement of Plastic Strain Using Laser Speckle, I. Mesurement of Plastic Strain in Steel Specimens by Means of Intensity Distribution of Laser Speckle.

1994 ◽  
Vol 43 (489) ◽  
pp. 696-702 ◽  
Author(s):  
Akira KATO ◽  
Mitsuo KAWAMURA
Keyword(s):  
Plastic Strain ◽  
Intensity Distribution ◽  
Laser Speckle ◽  
Contact Measurement

Plastic strain measurement in polypropylene using laser speckle technique

1995 ◽  
Vol 48 (1-4) ◽  
pp. 307-313 ◽  
Author(s):  
C.J. Tay ◽  
C.M. Yap ◽  
H.M. Shang ◽  
T.E. Tay
Keyword(s):  
Plastic Strain ◽  
Strain Measurement ◽  
Laser Speckle

scholarly journals Laser Speckles from Multimode Fiber under Scrambling

2012 ◽  
Vol 8 (S293) ◽  
pp. 385-387
Author(s):  
Hongfei Yu ◽  
Jian Han ◽  
Dong Xiao
Keyword(s):  
Laser Beam ◽  
Line Profile ◽  
Intensity Distribution ◽  
Laser Speckle ◽  
Field Pattern ◽  
Far Field ◽  
Output Beam ◽  
Far Field Pattern ◽  
Multi Mode ◽  
Laser Speckles

AbstractWhen a laser beam transmits through a multi-mode fiber, speckles show in the output beam. In this work, we study the laser speckle under static and dynamic scrambling by the histogram and line profile of far-field pattern. The results show that static scrambling has little effect on the intensity distribution. The dynamic scrambling reduces the speckles without changing the line profile. Two possible explanations are proposed.

scholarly journals Correcting the detrimental effects of nonuniform intensity distribution on fiber-transmitting laser speckle imaging of blood flow

2011 ◽  
Vol 20 (1) ◽  
pp. 508 ◽  
Author(s):  
Hongyan Zhang ◽  
Pengcheng Li ◽  
Nengyun Feng ◽  
Jianjun Qiu ◽  
Bing Li ◽  
...  
Keyword(s):  
Blood Flow ◽  
Intensity Distribution ◽  
Laser Speckle ◽  
Laser Speckle Imaging ◽  
Speckle Imaging

Plastic Deformation in Microtomed Sections

1971 ◽  
Vol 29 ◽  
pp. 458-459
Author(s):  
J. Temple Black
Keyword(s):  
Plastic Deformation ◽  
Plastic Strain ◽  
Applied Stress ◽  
Elastic Strain ◽  
High Strain ◽  
Tool Material ◽  
Cutting Edge ◽  
Material Structure ◽  
Geometrical Constraints

The output of the ultramicrotomy process with its high strain levels is dependent upon the input, ie., the nature of the material being machined. Apart from the geometrical constraints offered by the rake and clearance faces of the tool, each material is free to deform in whatever manner necessary to satisfy its material structure and interatomic constraints. Noncrystalline materials appear to survive the process undamaged when observed in the TEM. As has been demonstrated however microtomed plastics do in fact suffer damage to the top and bottom surfaces of the section regardless of the sharpness of the cutting edge or the tool material. The energy required to seperate the section from the block is not easily propogated through the section because the material is amorphous in nature and has no preferred crystalline planes upon which defects can move large distances to relieve the applied stress. Thus, the cutting stresses are supported elastically in the internal or bulk and plastically in the surfaces. The elastic strain can be recovered while the plastic strain is not reversible and will remain in the section after cutting is complete.

Comparison of Substructures Between Uniaxial and Biaxial Deformation in 1100-0 Aluminum

1981 ◽  
Vol 39 ◽  
pp. 52-53
Author(s):  
D. L. Rohr ◽  
S. S. Hecker
Keyword(s):  
Plastic Strain ◽  
Cell Walls ◽  
Room Temperature ◽  
Mechanical Response ◽  
Biaxial Tension ◽  
Initial Deformation ◽  
Uniaxial Deformation ◽  
Biaxial Deformation ◽  
Stress States ◽  
Comprehensive Study

As part of a comprehensive study of microstructural and mechanical response of metals to uniaxial and biaxial deformations, the development of substructure in 1100 A1 has been studied over a range of plastic strain for two stress states.Specimens of 1100 aluminum annealed at 350 C were tested in uniaxial (UT) and balanced biaxial tension (BBT) at room temperature to different strain levels. The biaxial specimens were produced by the in-plane punch stretching technique. Areas of known strain levels were prepared for TEM by lapping followed by jet electropolishing. All specimens were examined in a JEOL 200B run at 150 and 200 kV within 24 to 36 hours after testing.The development of the substructure with deformation is shown in Fig. 1 for both stress states. Initial deformation produces dislocation tangles, which form cell walls by 10% uniaxial deformation, and start to recover to form subgrains by 25%. The results of several hundred measurements of cell/subgrain sizes by a linear intercept technique are presented in Table I.

Structure images of Si, Ge and Mos2 crystals and some application to radiation damage studies

1978 ◽  
Vol 36 (1) ◽  
pp. 292-293 ◽  
Author(s):  
K. Izui ◽  
T. Nishida ◽  
S. Furuno ◽  
H. Otsu ◽  
S. Kuwabara
Keyword(s):  
Radiation Damage ◽  
Exposure Time ◽  
Gaussian Distribution ◽  
Intensity Distribution ◽  
Chromatic Aberration ◽  
Magnetic Lens

Recently we have observed the structure images of silicon in the (110), (111) and (100) projection respectively, and then examined the optimum defocus and thickness ranges for the formation of such images on the basis of calculations of image contrasts using the n-slice theory. The present paper reports the effects of a chromatic aberration and a slight misorientation on the images, and also presents some applications of structure images of Si, Ge and MoS2 to the radiation damage studies.(1) Effect of a chromatic aberration and slight misorientation: There is an inevitable fluctuation in the amount of defocus due to a chromatic aberration originating from the fluctuations both in the energies of electrons and in the magnetic lens current. The actual image is a results of superposition of those fluctuated images during the exposure time. Assuming the Gaussian distribution for defocus, Δf around the optimum defocus value Δf0, the intensity distribution, I(x,y) in the image formed by this fluctuation is given by

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