The concept of the mobilized domain: how it can explain and predict the forces exerted by a cohesive granular avalanche on an obstacle
Open access
Date
2022-05Type
- Journal Article
ETH Bibliography
no
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Abstract
The calculation of the impact pressure on obstacles in granular flows is a fundamental issue of practical relevance, e.g. for snow avalanches impacting obstacles. Previous research shows that the load on the obstacle builds up, due to the formation of force chains originating from the obstacle and extending into the granular material. This leads to the formation of a mobilized domain, wherein the flow is influenced by the presence of the obstacle. To identify the link between the physical mobilized domain properties and the pressure exerted on obstacles, we simulate subcritical cohesionless and cohesive avalanches of soft particles past obstacles with circular, rectangular or triangular cross-section using the Discrete Element Method. Our results show that the impact pressure decreases non-linearly with increasing obstacle width, regardless of the obstacle’s cross-section. While the mobilized domain size is proportional to the obstacle width, the pressure decrease with increasing width originates from the jammed material inside the mobilized domain. We provide evidence that the compression inside the mobilized domain governs the pressure build-up for cohesionless subcritical granular flows. In the cohesive case, the stress transmission in the compressed mobilized domain is further enhanced, causing a pressure increase compared with the cohesionless case. Considering a kinetic and a gravitational contribution, we are able to calculate the impact pressure based on the properties of the mobilized domain. The equations used for the pressure calculation in this article may be useful in future predictive pressure calculations based on mobilized domain properties. Show more
Permanent link
https://doi.org/10.3929/ethz-b-000619971Publication status
publishedExternal links
Journal / series
Granular MatterVolume
Pages / Article No.
Publisher
SpringerSubject
Cohesive granular flow; Impact pressure calculation; Impact pressure on obstacles; Mohibilized domainOrganisational unit
09795 - Gaume, Johan / Gaume, Johan
09795 - Gaume, Johan / Gaume, Johan
Related publications and datasets
Is supplemented by: https://doi.org/10.5281/zenodo.4079357
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ETH Bibliography
no
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