Fatemeh Rezaei^1,2,*, Milan Gaff^1,3,4,*, Róbert Nemeth⁵, Jerzy Smardzewski⁶, Peter Niemz⁷, Haitao Li^8,9, Anil Kumar Sethy^1,10, Luigi Todaro¹¹, Gourav Kamboj¹, Sumanta Das¹, Roberto Corleto¹, Gianluca Ditommaso¹, Miklós Bak⁵

Journal of Renewable Materials, Vol.11, No.8, pp. 3277-3296, 2023, DOI:10.32604/jrm.2023.028352

Abstract The performance of engineered wood products is highly associated with proper bonding and an efficient cutting method. This paper investigates the influence of CO₂ laser cutting on the wetting properties, the modified chemical component of the laser-cut surface, and the strength and adhesive penetration near the bondline. Beechwood is cut by the laser with varying processing parameters, cutting speeds, gas pressures, and focal point positions. The laser-cut samples were divided into two groups, sanded and non-sanded samples. Polyvinyl acetate adhesive (PVAc) was used to bond the groups of laser-cut samples. After assembly with cold pressing, the tensile shear test was… More >

Lin Fang^1,2,*, Mengjun Wu^1,2, Bin Wu³, Honglin Li⁴, Chenhao He^5,*, Fan Sun⁵

CMES-Computer Modeling in Engineering & Sciences, Vol.130, No.3, pp. 1649-1668, 2022, DOI:10.32604/cmes.2022.018527

Abstract Based on the theories of the gas seepage in coal seams and the deformation of the coal-rock medium, the gas seepage field in coal-rock mass is coupled with the deformation field of the coal-rock mass to establish a fluid-structure interaction model for the interaction between coal gas and coal-rock masses. The outburst process in coal-rock masses under the joint action of gas pressure and crustal stress is simulated using the material point method. The simulation results show the changes in gas pressure, velocity distribution, maximum principal stress distribution, and damage distribution during the process of the coal and gas outburst,… More >

Yi Xue^1,2,*, Faning Dang², Rongjian Li², Fei Liu³

CMES-Computer Modeling in Engineering & Sciences, Vol.115, No.3, pp. 345-358, 2018, DOI: 10.3970/cmes.2018.08052

Abstract Adsorption deformation significantly affects the seepage characteristics of coal. However, effect of sorption time on coal permeability and gas pressure has not been investigated systematically. In this study, the sorption experiment of coal samples is conducted to elaborate the importance of sorption equilibration time. Then a coupled coal deformation and gas flow model is established considering the sorption characteristic and permeability evolution. This coupled model is implemented through finite element method to analyze the effect of sorption time on coal permeability and gas pressure. The simulation results reveal that the gas pressure of the coal will change with the adsorption… More >

Yi Xue^1,2,3

CMES-Computer Modeling in Engineering & Sciences, Vol.113, No.4, pp. 429-441, 2017, DOI:10.3970/cmes.2017.113.429

Abstract The lack of research on the effect of diffusion on methane extraction leads to low methane concentration and low utilization. The Comsol Multiphysics software is used to solve the numerical gas and solid coupled model which considers the diffusion of coal matrix, fracture seepage, permeability evolution and coal deformation. The simulation results reveal the effect of diffusion process on methane migration. The gas diffusion rate is relatively high in the initial stage. With the increase in time, the difference between coal fractures and coal matrix blocks becomes lower and the gas diffusion rate decreases gradually. The gas seepage rate decreases… More >

Xuebo Zhang^{1, 2, 3}, Zhiwei Jia^{1, 2, 3, *}

FDMP-Fluid Dynamics & Materials Processing, Vol.15, No.1, pp. 53-61, 2019, DOI:10.32604/fdmp.2019.04779

Abstract The influence of ground stress was quantitatively analyzed on coal seam gas pressure and gas content in this paper. Mining activities in coal mine can result in stress concentration in the coal (rock) body around the mining space, but porosity of the coal seam would not change too much. Therefore, gas pressure and gas content in the coal seam are slightly affected. Studies showed that the free gas was gradually transformed into adsorbed gas, and the gas adsorption volume was small, and then gas pressure increases roughly linearly when the porosity decreased because of stress influence. Additionaly, when porosity of… More >

Yi Xue^1,2,3, Faning Dang², Rongjian Li², Liuming Fan², Qin Hao⁴, Lin Mu², Yuanyuan Xia²

CMC-Computers, Materials & Continua, Vol.54, No.1, pp. 43-59, 2018, DOI:10.3970/cmc.2018.054.043

Abstract In the seepage-stress-damage coupled process, the mechanical properties and seepage characteristics of coal are distinctly different between pre-peak stage and post-peak stage. This difference is mainly caused by damage of coal. Therefore, in the process of seepage and stress analysis of coal under the influence of excavation or mining, we need to consider the weakening of mechanical properties and the development of fractures of damaged coal. Based on this understanding, this paper analyzes the influence of damage on mechanics and seepage behavior of coal. A coupled model is established to analyze the seepage-stress-damage coupled process of coal. This model implemented… More >