DOI: 10.5194/tc-14-131-2020
论文题名: Modeling snow slab avalanches caused by weak-layer failure - Part 2: Coupled mixed-mode criterion for skier-triggered anticracks
作者: Rosendahl P.L. ; Weißgraeber P.
刊名: Cryosphere
ISSN: 19940416
出版年: 2020
卷: 14, 期: 1 起始页码: 131
结束页码: 145
语种: 英语
英文关键词: avalanche
; compliance
; crack propagation
; failure analysis
; fracture mechanics
; fracture toughness
; numerical model
; slab
; slope angle
; snow cover
; snowpack
英文摘要: Using the analytical model presented in Part 1 of this two-part paper, a new conceptual understanding of anticrack nucleation in weak layers is proposed. To obtain a sufficient condition for onset of failure, two necessary conditions must be satisfied simultaneously: (i) the weak layer must be overloaded in terms of stress and (ii) the initiating crack must release enough energy for the formation of new surfaces. This so-called coupled criterion was proposed by Leguillon (2002). No assumptions on initial defects within the weak layer are needed. Instead, the failure criterion provides both critical loading and the size of initiating cracks. It only requires the fundamental material properties strength and fracture toughness as inputs. Crack initiation and subsequent propagation are covered by a single criterion containing both a strength-of-materials and a fracture mechanics condition. Analyses of skier-loaded snowpacks show the impact of slab thickness and slope angle on critical loading and crack initiation length. In the limit cases of very thick slabs and very steep slopes, we obtain natural avalanche release. A discussion of different mixed-mode stress and energy criteria reveals that a wrong choice of mixed-mode hypotheses can yield unphysical results. The effect of material parameters such as density and compliance on weak-layer collapse is illustrated. The framework presented in this two-part series harnesses the efficiency of closed-form solutions to provide fast and physically sound predictions of critical snowpack loads using a new conceptual understanding of mixed-mode weak-layer failure. It emphasized the importance of both stress and energy in avalanche release. © Author(s) 2020. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/164572
Appears in Collections: 气候变化与战略
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作者单位: 2phi GbR, Tübingen, Germany; Department of Mechanical Engineering, Technische Universität Darmstadt, Darmstadt, Germany; Robert Bosch GmbH, Corporate Research and Advance Engineering, Renningen, Germany; ARENA2036 research campus, Universität Stuttgart, Stuttgart, Germany
Recommended Citation:
Rosendahl P.L.,Weißgraeber P.. Modeling snow slab avalanches caused by weak-layer failure - Part 2: Coupled mixed-mode criterion for skier-triggered anticracks[J]. Cryosphere,2020-01-01,14(1)