Modeling of compressible self-organized granular media under static load

2013 ◽  
Author(s):  
Mikhail N. Skachkov
Keyword(s):  
Granular Media ◽  
Static Load ◽  
Self Organized

Material remodeling and unconventional gaits facilitate locomotion of a robophysical rover over granular terrain

2020 ◽  
Vol 5 (42) ◽  
pp. eaba3499 ◽  
Author(s):  
Siddharth Shrivastava ◽  
Andras Karsai ◽  
Yasemin Ozkan Aydin ◽  
Ross Pettinger ◽  
William Bluethmann ◽  
...  
Keyword(s):  
Granular Media ◽  
Autonomous Robots ◽  
Robot Dynamics ◽  
Force Measurements ◽  
Lunar Rover ◽  
Self Organized ◽  
Wheeled Vehicle ◽  
Substrate Disturbance ◽  
Resistive Force Theory ◽  
Granular Drag

Autonomous robots and vehicles must occasionally recover from locomotion failure in loosely consolidated granular terrain. Recent mobility challenges led NASA Johnson Space Center to develop a prototype robotic lunar rover Resource Prospector 15 (RP15) capable of wheeled, legged, and crawling behavior. To systematically understand the terradynamic performance of such a device, we developed a scaled-down rover robot and studied its locomotion on slopes of dry and wet granular media. Addition of a cyclic-legged gait to the robot’s wheel spinning action changes the robot dynamics from that of a wheeled vehicle to a locomotor paddling through frictional fluid. Granular drag force measurements and modified resistive force theory facilitate modeling of such dynamics. A peculiar gait strategy that agitates and cyclically reflows grains under the robot allows it to “swim” up loosely consolidated hills. Whereas substrate disturbance typically hinders locomotion in granular media, the multimode design of RP15 and a diversity of possible gaits facilitate formation of self-organized localized frictional fluids that enable effective robust transport.

scholarly journals Quasistatic kinetic avalanches and self-organized criticality in deviatorically loaded granular media

2021 ◽  
Vol 104 (2) ◽  
Author(s):  
Jordi Baró ◽  
Mehdi Pouragha ◽  
Richard Wan ◽  
Jörn Davidsen
Keyword(s):  
Granular Media ◽  
Self Organized ◽  
Self Organized Criticality

Problem behavior in autism spectrum disorders: A paradigmatic self-organized perspective of network structures

2019 ◽  
Vol 42 ◽  
Author(s):  
Lucio Tonello ◽  
Luca Giacobbi ◽  
Alberto Pettenon ◽  
Alessandro Scuotto ◽  
Massimo Cocchi ◽  
...  
Keyword(s):  
Autism Spectrum Disorder ◽  
Problem Behaviors ◽  
Autism Spectrum ◽  
The Self ◽  
Network Structures ◽  
Self Organized ◽  
Critical Equilibrium ◽  
Self Organized Criticality ◽  
Acute Agitation ◽  
Spectrum Disorders

AbstractAutism spectrum disorder (ASD) subjects can present temporary behaviors of acute agitation and aggressiveness, named problem behaviors. They have been shown to be consistent with the self-organized criticality (SOC), a model wherein occasionally occurring “catastrophic events” are necessary in order to maintain a self-organized “critical equilibrium.” The SOC can represent the psychopathology network structures and additionally suggests that they can be considered as self-organized systems.

A photoelastic clinical study of the static load distributionat the stump/socket interface of PTB sockets

2005 ◽  
Vol 29 (3) ◽  
pp. 291-302 ◽  
Author(s):  
P. Sewell ◽  
J. Vinney ◽  
S. Noroozi ◽  
R. Amali ◽  
S. Andrews
Keyword(s):  
Clinical Study ◽  
Static Load ◽  
Socket Interface

Role of contact couples and couple stress in the behaviour of granular media

1998 ◽  
Vol 08 (PR8) ◽  
pp. Pr8-87-Pr8-94
Author(s):  
F. Dedecker ◽  
Ph. Dubujet ◽  
B. Cambou
Keyword(s):  
Couple Stress ◽  
Granular Media

Validation of SST 300 bearing casing for SST 200 bearing casing in static load condition

2011 ◽  
Vol 3 (7) ◽  
pp. 277-278
Author(s):  
Jinesh Shah ◽  
◽  
Mohammad Azim Aijaz ◽  
Pratik Kikani ◽  
Sagarkumar Shah ◽  
...  
Keyword(s):  
Static Load ◽  
Load Condition

Avalanche Stratification - Experimental Tests of the “Metastable Wedge” and “Continuous Flow” Models

2000 ◽  
Vol 627 ◽  
Author(s):  
M. E. Swanson ◽  
M. Landreman ◽  
J. Michel ◽  
J. Kakalios
Keyword(s):  
Continuous Flow ◽  
Granular Media ◽  
Experimental Tests ◽  
Coarse Sand ◽  
Angle Of Repose ◽  
Flow Models ◽  
Maximum Angle ◽  
Stratification Effect ◽  
Upward Moving ◽  
Moving Layer

ABSTRACTWhen an initially homogeneous binary mixture of granular media such as fine and coarse sand is poured near the closed edge of a “quasi-two-dimensional” Hele-Shaw cell consisting of two vertical transparent plates held a narrow distance apart, the mixture spontaneously forms alternating segregated layers. Experimental measurements of this stratification effect are reported in order to determine which model, one which suggests that segregation only occurs when the granular material contained within a metastable heap between the critical and maximum angle of repose avalanches down the free surface, or one for which the segregation results from smaller particles becoming trapped in the top surface and being removed from the moving layer during continuous flow. The result reported here indicate that the Metastable Wedge model provides a natural explanation for the initial mixed zone which precedes the formation of the layers, while the Continuous Flow model explains the observed upward moving kink of segregated material for higher granular flux rates, and that both mechansims are necessary in order to understand the observed pairing of segregated layersfor intermediate flow rates and cell separations.

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