Frictional characteristics of granular system under high pressure

Cao, Miaoyan; Peng, Yaxin; Zhao, Changchun; Guo, Dong; Du, Bing

doi:10.1007/s11771-016-0363-x

Cited by 8 publications

(2 citation statements)

References 26 publications

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“…In order to study the rule of change of the CO concentration with time in the tunnel, the pressure-entry air blower is set at 20 m from the boring face and the wind speed is 9 m/s. The distribution of CO in the human respiratory zone Y = 1.6 m plane in the tunnel is analyzed by taking the moments of t = 60 s, 300 s, 600 s, 900 s, 1200 s, 1500, and 1800 s in the time period of ventilation for 30 min, respectively . The variation of the CO with time is shown in Figure…”

Section: Resultsmentioning

confidence: 99%

CO Diffusion Study and Spatial and Temporal Variation Modeling during the Construction Period of the Plateau Railroad Tunnel

Liu,

Zhao,

Wang

et al. 2023

ACS Omega

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In order to investigate the diffusion law of CO gas in the vicinity of the tunnel boring face of the plateau long tunnel, to improve the efficiency of tunnel smoke exhaust, and to derive the spatial-temporal variation model of CO concentration for predicting the concentration of CO at different times and in different cross sections under specific environments, a CO diffusion model of a tunnel in Yunnan was established by using Ansys Fluent Fluid Simulation Software, and the CO transport characteristics under different conditions were simulated by taking the ventilation time, wind speed, and location of the air ducts as the influencing factors. The results show that the wind flows from the mouth of the wind pipe after the wind speed decreases, the diffusion area increases and arrives at the face of the direction of the rebound in the jet stream of new wind, and the return wind under the joint action of the vortex produced obviously, to reach the wind pipe mouth after the tunnel wind flow field, basically tends to stabilize. When the wind pipe mouth was arranged in the arch waist, 20 m away from the boring face, the inlet wind speed was 9 m/s and the ventilation time was 30 min; the CO concentration in the tunnel was reduced to below the maximum allowable concentration value. Moreover, the concentration of CO in the tunnel at the moment of 15 min of ventilation has a nonlinear positive correlation with the change of distance L from the boring face, while at the cross section of the air outlet of the wind pipe L = 20 m, the ventilation time is from 1 to 30 min and the concentration of CO at the cross section has a nonlinear decreasing trend with the ventilation time, which can be deduced according to the different space–time change models.

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Section: Resultsmentioning

confidence: 99%

CO Diffusion Study and Spatial and Temporal Variation Modeling during the Construction Period of the Plateau Railroad Tunnel

Liu,

Zhao,

Wang

et al. 2023

ACS Omega

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“…Numerical simulations using the discrete element method (DEM) have become an effective tool to research different dynamic mechanisms occurring at the mesoscopic and microscopic scale in granular matter systems [20][21][22][23][24][25]. In this paper, a 2D numerical model of the single-direction granular compacting system is established to investigate the multi-scale mechanical behaviors of granular materials.…”

Section: Dem Modelmentioning

confidence: 99%

Numerical analysis of multi-scale mechanical theory of densified powder compaction

Meng

Liu

Qin

2018

J Braz. Soc. Mech. Sci. Eng.

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Multi-scale mechanical theory of powder compacting is the foundation for improving the quality of the product made by powder metallurgy. Aimed at powder compacting process, a 2D numerical model of the single-direction granular compacting system is established by the discrete element method. Using this DEM numerical model, the stress-strain responses, directional distributions of velocity vector and distributions of force chains in the compacting stage are studied. Research results show that powder granules successively go through the phase transformation processes of flow state, quasi-static and jamming state in the compacting process. Clearly, it is noted that velocity direction distribution of powder granule is closely related to the granule flow state, and dilatancy behavior of powder granule is a main reason for influencing the velocity direction distribution of powder granules under the quasi-static. The contact normal force, contact tangential force and contact force all comply with a power law forms, and the strength of force chains between powder granules increases with increased inter-granule friction coefficient.

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FE-DE coupling analysis of AZ31B sheet solid granule medium forming based on GTN model

Cao

Han

Jia

et al. 2020

Int J Adv Manuf Technol

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Frictional characteristics of granular system under high pressure

Cited by 8 publications

References 26 publications

CO Diffusion Study and Spatial and Temporal Variation Modeling during the Construction Period of the Plateau Railroad Tunnel

CO Diffusion Study and Spatial and Temporal Variation Modeling during the Construction Period of the Plateau Railroad Tunnel

Numerical analysis of multi-scale mechanical theory of densified powder compaction

FE-DE coupling analysis of AZ31B sheet solid granule medium forming based on GTN model

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