DOI: 10.1002/2013JD020352
论文题名: Observation of the microstructural evolution of snow under uniaxial compression using X-ray computed microtomography
作者: Wang X. ; Baker I.
刊名: Journal of Geophysical Research Atmospheres
ISSN: 21698996
出版年: 2013
卷: 118, 期: 22 起始页码: 12371
结束页码: 12382
语种: 英语
英文关键词: pressure sintering
; snow metamorphism
; X-ray computed microtomography
Scopus关键词: Compression testing
; Computerized tomography
; Deformation
; Mechanical properties
; Microstructural evolution
; Scanning electron microscopy
; Sintering
; Temperature
; Tomography
; X rays
; Evolution of structures
; Fracturing process
; Scanning electron microscopy image
; Snow metamorphisms
; Stress-displacement
; Structure modeling
; Uni-axial compression
; X-ray computed microtomography
; Avalanches (snowslides)
; compression
; deformation
; fracture
; mechanical property
; observational method
; snow avalanche
; snow cover
; tomography
英文摘要: The relationship between snow microstructure and its mechanical properties is crucial for modeling the microstructural cause of snow avalanches. In this paper, the knowledge gap between snow microstructural evolution and overburden is bridged by combining compression tests with X-ray computed microtomography (micro-CT). Continuous compression tests and interrupted compression tests were performed on three types of snow (fresh low-temperature snow, fresh high-temperature snow, and sintered low-temperature snow with densities ranging from 100 to 350 kg/m3) to investigate the effects of initial structure on both the stress-displacement curve and structural changes during the compression test. Three-dimensional micro-CT images and scanning electron microscopy images showed that well-connected structures of sintered snow contribute to a more rapid stress increase during deformation. By combining the analyses of the specific surface area, structure model index, and structure thickness, it is shown that compression tests at a fixed temperature, loading rate, and density snow metamorphism can be regarded as an accelerated pressure sintering process. However, when extremely low-density snow (50 kg/m 3) was subjected to compression testing, the same evolution of structure parameters was again found, but fracture of snowflakes was also observed. The overall process of low-density snow deformation can be explained as a combination of fracturing and sintering but with the sintering predominating. Key Points Sintered snow has more rapid load increase during compression test Snow metamorphism under overburden is an accelerated sintering process Low-density snow under compression has both sintering and fracturing processes ©2013. American Geophysical Union. All Rights Reserved. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/63134
Appears in Collections: 影响、适应和脆弱性 气候减缓与适应
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作者单位: Thayer School of Engineering, Dartmouth College, 14 Engineering Dr., Hanover, NH 03755-8000, United States
Recommended Citation:
Wang X.,Baker I.. Observation of the microstructural evolution of snow under uniaxial compression using X-ray computed microtomography[J]. Journal of Geophysical Research Atmospheres,2013-01-01,118(22)