A pressure-sensitive rheological origin of high friction angles of granular matter observed in NASA–MGM project  

作　　者：程晓辉 肖世泽 杨森 赵乃峰 Alex Sixie Cao Xiaohui Cheng;Shize Xiao;Sen Yang;Naifeng Zhao;Alex Sixie Cao(Department of Civil Engineering,Tsinghua University,Beijing 100084,China;College of Transportation Engineering,Nanjing Tech University,Nanjing 211816,China;Institute of Structural Engineering,ETH Zurich,Zurich 8092,Switzerland)

机构地区：[1]Department of Civil Engineering,Tsinghua University,Beijing 100084,China [2]College of Transportation Engineering,Nanjing Tech University,Nanjing 211816,China [3]Institute of Structural Engineering,ETH Zurich,Zurich 8092,Switzerland

出　　处：《Chinese Physics B》2024年第6期559-567,共9页中国物理B（英文版）

基　　金：Project supported by the ESA-CMSA/CSU Space Science and Utilization Collaboration Program。

摘　　要：An abnormally high peak friction angle of Ottawa sand was observed in(National Aeronautics and Space Administration) NASA–(Mechanics of Granular Materials) MGM tests in microgravity conditions on the space shuttle. Previous investigations have been unsuccessful in providing a constitutive insight into this behavior of granular materials under extremely low effective stress conditions. Here, a recently proposed unified constitutive model for transient rheological behavior of sand and other granular materials is adopted for the analytical assessment of high peak friction angles. For the first time, this long-eluded behavior of sand is attributed to a hidden rheological transition mechanism, that is not only rate-sensitive, but also pressure-sensitive. The NASA–MGM microgravity conditions show that shear-tests of sand can be performed under abnormally low confining stress conditions. The pressure-sensitive behavior of granular shearing that is previously ignored is studied based on the μ(I) rheology and its variations. Comparisons between the model and the NASA microgravity tests demonstrate a high degree of agreement. The research is highly valid for pressure-sensitive and rate-dependent problems that occur during earthquakes, landslides, and space exploration.

关 键 词：granular matter MICROGRAVITY pressure-sensitive NASA–MGM 

分 类 号：O341[理学—固体力学] V416[理学—力学]