LAT Laser-Aided Tomography
We usually cannot see inside a 3-D granular assembly. However the mechanical properties of the assembly is greatly affected by its granular structure. LAT(Laser-Aided Tomography) is developed by Konagai et al.[1] as an innovative visualization tool for such granular materials. In LAT crushed glass grains are saturated by the liquid which has the same refractive index as the glass. An intense laser-light sheet is then passed through the transparent model which illuminates the contours of all particles within the optically cut cross-section. By changing the cross-section, we can obtain the 3D information on the granular structure.

[1] Konagai, K., Tamura, C., Rangelow, P. and Matsushima, T.: Laser-Aided Tomography: A Tool for Visualization of Changes in the Fabric of Granular Assemblage, Structural Engineering/ Earthquake Engineering, Vol.9, No.3, pp.193s-201s, JSCE, 1992.
[2] Konagai, K., Matsushima, T. and Sato, T.: Dependence on Frequency of Dynamic Inter-particle Dislocation within a Slope, Structural Engineering/ Earthquake Engineering, Vol.11, No.2, pp.93s-101s, JSCE, 1994.
[3] Matsushima, T., Ishii, T. and Konagai, K.: Observation of Grain Motion in the interior of a PSC Test Specimen by Laser-Aided Tomography, Soils & Foundations, Vol. 42, No. 5, pp.27-36, 2002.
[4]Matsushima, T., Saomoto, H., Tsubokawa, Y., Yamada, Y.: Grain Rotation versus Continuum Rotation during Shear Deformation of Granular Assembly, Soils & Foundations, Vol.43, No.4, pp.95-106, 2003.8.
[5]SAOMOTO, Hidetaka, Takashi MATSUSHIMA, and Yasuo YAMADA. "Development of LAT-PIV visualization technique for particle-fluid system." STRUCTURAL ENGINEERING/EARTHQUAKE ENGINEERING 24.2 (2007): 123S-130S.
latanim.gif
Scanning by Laser-light sheet

Obtained image

Reconstructed image (1)

Reconstructed image (2)


Application into bearing capacity test of footing on a slope (avi)



[Contents in Japanese]

Matsushima, Ishii and Konagai: 日経サイエンス, 2000.08.(pdf)

松島亘志、小長井一男：LATを用いた３次元粒状体内部構造および粒子運動の可視化, 土と基礎、講座「土のメカニックス入門　-ミクロからマクロへ-」、Vol.50, No.6, pp.37-42, 2002.(pdf)

LAT説明ポスター(pdf)