Article
Energy & Fuels
Pingxin Xia, Longtan Shao, Wen Deng
Summary: This paper introduces a concept of strain ratio for granular soils under quasi-elastic state and measures it through experimental tests. It is found that the strain ratio is consistent with Poisson's ratio only in the initial shear stage, but there is a significant deviation in subsequent shearing.
GEOMECHANICS FOR ENERGY AND THE ENVIRONMENT
(2023)
Article
Construction & Building Technology
Xing Wang, Yi Shan, Jie Cui, Yu Zhong, Jian-Hua Shen, Xin-Zhi Wang, Chang-Qi Zhu
Summary: This study conducted tests on CGS to investigate the effects of relative density and effective confining pressure on its dilatancy. An empirical dilatancy equation for calcareous sand was proposed and validated. The study also compared different dilatancy equations and found a linear relationship between dilatancy ratio and stress ratio-related parameter.
CONSTRUCTION AND BUILDING MATERIALS
(2022)
Article
Materials Science, Multidisciplinary
Fanjing Meng, Minghua Pang, Shaozhen Hua, Huabo Liu, Lijie Ma
Summary: This study experimentally and numerically investigates the friction behavior of lubricated granular medium. The experimental results show that the nonlinear trend of friction force and friction coefficient with time is influenced by shear velocity and pressure load. The numerical simulation reveals the impact of force chain evolution and granular flow characteristics on friction nonlinearity.
RESULTS IN PHYSICS
(2022)
Article
Engineering, Chemical
Ravindra S. Ghodake, Pankaj Doshi, Ashish Orpe
Summary: This study investigates the gravity driven flow of millimetric granular material coated with micron-sized lubricant particles. The experimental results show a non-monotonic behavior in the volumetric flow rate of the particles with increasing lubricant concentration. This behavior is attributed to the reduction of inter-particle friction caused by the adherence of lubricant particles to the granular surface, as well as the damping effect on inter-particle collision at higher lubricant concentrations.
Article
Engineering, Mechanical
Artur Wojcik, Thomas G. Mathia
Summary: This paper analyzes the friction phenomenon of granular cereal materials at low sliding velocities. It is found that the friction force exhibits periodic changes and three characteristic phases are identified. The study confirms the significant influence of velocity and load on the nature of friction force changes.
TRIBOLOGY INTERNATIONAL
(2022)
Article
Materials Science, Multidisciplinary
Julian M. Gomez-Paccapelo, Angel A. Santarossa, H. Daniel Bustos, Luis A. Pugnaloni
Summary: A granular gripper uses Reynold's dilatancy to hold objects by jamming granular material inside a membrane, preventing deformation of the material and resisting external forces. The maximum holding force in the frictional holding regime does not depend on the granular material used, but rather on the penetration depth of the object in the gripper. By plotting maximum holding force against penetration depth, results for various granular materials can be collapsed into a single curve for estimating holding force in gripping operations.
Article
Mathematics, Applied
Gourav Agrawal, Abhinav Gupta, Rajib Chowdhury, Anupam Chakrabarti
Summary: The study examines a SIMP-based robust topology optimization design for NPR metamaterials under material uncertainty, showing that RTO produces more stable designs with variations ranging from 1.72% to 2.54%, significantly lower than deterministic topology optimization.
FINITE ELEMENTS IN ANALYSIS AND DESIGN
(2022)
Article
Mechanics
A. M. Taylor-Noonan, G. A. Siemens, M. A. Cabrera, N. M. Arpin, F. Parera Morales, W. A. Take
Summary: The granular column collapse experiment explores the influence of fluid filling voids on the shear behavior of columns, impacting stability and runout length. Dilative or contractive behavior at the pore level affects pore fluid pressure, in turn defining stability or instability of granular columns. Air entry within saturated columns significantly influences the mobility of densely packed columns subject to collapse.
Article
Engineering, Mechanical
Y. C. Chung
Summary: This paper investigates the effect of obstacles on granular stresses and stress ratios in 3D granular silo flows using discrete element method (DEM). Results show that the blocking effect from the obstacles and the hopper wall of the silos led to a significant increase in normal and shear stresses. The obstructed granular silo flows exhibited strong anisotropy not only in normal stresses, but also in shear stresses, and the stress ratio can appreciably deviate from unity.
INTERNATIONAL JOURNAL OF MECHANICAL SCIENCES
(2023)
Article
Geochemistry & Geophysics
I. R. Ashman, D. R. Faulkner
Summary: The composition of fault rocks, especially the proportion of clay, plays a crucial role in their frictional behavior and volume changes during fault slip. Clay-rich gouges exhibited measurable dilation upon a velocity increase, impacting the frictional strength and slip stability. This study provides essential insights towards understanding the slip behavior of faults, contributing to earthquake nucleation and sustained slow slip.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2023)
Article
Engineering, Mechanical
Qiang Li, Fenghua Su, Gongbin Tang, Xing Xu, Yanjun Chen, Jianfang Sun
Summary: This study uses first-principles to show that bilayer black phosphorus is insensitive to high-load friction. This conclusion is significant for lubrication design and microscale mechanism analysis in engineering applications.
TRIBOLOGY INTERNATIONAL
(2022)
Article
Engineering, Electrical & Electronic
Yan Xu, Weikun Jia, Yudong Zhang, Fangyong Wang, Gang Zhao, Dongyang Zang
Summary: In this paper, Ag-IPMC was prepared using a chemical reduction method on a Nafion-117 membrane with Ag electrode surface coating. The key preparation process and mechanical properties of Ag-IPMC were determined and analyzed, showing the feasibility and purity of the silver coating.
SENSORS AND ACTUATORS A-PHYSICAL
(2021)
Article
Chemistry, Physical
Krzysztof K. Dudek, Ruben Gatt, Miroslaw R. Dudek, Joseph N. Grima
Summary: This study uses computer simulations to analyze the behavior and control of a specific anisotropic hierarchical mechanical metamaterial, showing that different hinge designs can achieve controllable deformation and enhance mechanical properties. The effects of system size and hinge stiffness variation on exhibited anisotropic behavior were also discussed. The concept presented could be applied in the design of highly efficient protective devices for specific applications.
Article
Engineering, Civil
Youcef Mahmoudi, Abdellah Cherif Taiba, Leila Hazout, Mostefa Belkhatir
Summary: This paper investigates the effects of over consolidation ratio, low plastic fines content, and depositional techniques on the mechanical characteristics of soil through triaxial compression tests. The results show significant variations in stress-strain behavior and friction angles under different conditions.
EUROPEAN JOURNAL OF ENVIRONMENTAL AND CIVIL ENGINEERING
(2022)
Article
Computer Science, Interdisciplinary Applications
Yizhao Gao, Qingshuo Hao, Peng Yu, Yuzhen Yu, He Lv
Summary: This study proposes a new constitutive model for granular soils, considering two types of volume variations and the state dependency of material density. The model includes compression and unloading curves considering grain crushing, and can accurately describe the stress-dilatancy relation under different experimental conditions.
COMPUTERS AND GEOTECHNICS
(2023)
Article
Construction & Building Technology
J. R. Villar-Garcia, J. Crespo, M. Moya, M. Guaita
MATERIALS AND STRUCTURES
(2018)
Article
Engineering, Chemical
Eutiquio Gallego, Jose Maria Fuentes, Joanna Wicek, Jose Ramon Villar, Francisco Ayuga
Article
Agronomy
Jose Ramon Villar-Garcia, Pablo Vidal-Lopez, Antonio J. Corbacho, Manuel Moya
INTERNATIONAL AGROPHYSICS
(2020)
Article
Agronomy
Eutiquio Gallego, Jose Maria Fuentes, Angel Ruiz, Gonzalo Hernandez-Rodrigo, Pedro Aguado, Francisco Ayuga
INTERNATIONAL AGROPHYSICS
(2020)
Article
Agronomy
Marcos A. Madrid, Jose M. Fuentes, Francisco Ayuga, Eutiquio Gallego
Summary: The determination of the angle of repose is essential for handling granular materials and designing equipment, while computational simulations are crucial to understand the micro-behavior of granular materials. The lack of a standard for experiments with granular materials of equivalent spherical radius larger than 2 mm poses a challenge. This study focuses on determining the rolling friction coefficient and finding an optimal procedure for the determination, as well as calibrating the coefficient using computational simulations.
Article
Agronomy
Francisco A. Sanchez-Crespo, Jose Rafael Marques da Silva, Maria T. Gomez-Villarino, Eutiquio Gallego, Jose M. Fuentes, Ana Garcia, Francisco Ayuga
Summary: This study successfully utilized new satellite missions, such as Sentinel-1, combined with differential interferometry to monitor erosion in agricultural basins. The technique not only allows for the study of water and tillage erosion, but also enables testing the effectiveness of erosion control measures and verifying the results of different management practices over time.
Article
Agronomy
Romulo Marcal Gandia, Wisner Coimbra de Paula, Estacio Antunes de Oliveira Junior, Gerardo Hernandez Rodrigo, Angel Ruiz Padin, Alberto Tascon Vegas, Francisco Carlos Gomes, Pedro Jose Aguado Rodriguez
Summary: Silos are widely used for storing granular and powdered materials. However, estimating the pressures exerted by the bulk material for designing and calculating the structure of the silo remains a challenge. The complex mechanical behavior of stored materials and limited number of experimental stations worldwide hinder progress in this field. This study aims to investigate the relationship between hopper angle, flow pattern, and vertical stress at the cylinder-to-hopper transition in slender silos.
Article
Agronomy
Manuel Moya, David Sanchez, Jose Ramon Villar-Garcia
Summary: This study investigates the mechanical properties of wheat, maize, and wood pellets stored in agricultural silos. The results show similar characteristics for wheat and maize compared to previous studies, while the mechanical properties of wood pellets are relatively new and scarce in the literature. The suggested reference values for the tested materials' properties can aid in silo load calculations using numerical methods.
Article
Geosciences, Multidisciplinary
J. D. Henao Casas, E. Fernandez Escalante, F. Ayuga
Summary: This study evaluates the potential of managed aquifer recharge (MAR) to offset the adverse effects of drought and water scarcity on groundwater storage. The results show that MAR can effectively alleviate the impacts of water scarcity and drought, providing an adaptation solution to climate change worldwide.
HYDROGEOLOGY JOURNAL
(2022)
Article
Forestry
Jose Ramon Villar-Garcia, Pablo Vidal-Lopez, Desiree Rodriguez-Robles, Manuel Moya Ignacio
Summary: This study focuses on the friction characteristics of Spanish chestnut sawn timber. The static and dynamic friction coefficients were determined for timber-to-timber and timber-to-steel joints. The results can be used for numerical simulations and as new data in wood standards.
Article
Agronomy
Eutiquio Gallego, Jose Maria Fuentes, Francisco Ayuga
Summary: The authors of this study have developed a Finite Element Model to predict wall pressures on oblique hoppers and have conducted several sensitivity analyses. The results demonstrate that the circumferential location and eccentricity of the outlet are the main factors affecting the pressures on oblique hoppers. A semi-empirical equation is proposed to estimate the expected pressures on oblique hoppers, which can accurately reflect the circumferential distribution of normal pressures.
INTERNATIONAL AGROPHYSICS
(2022)
Article
Environmental Sciences
Jose David Henao Casas, Enrique Fernandez Escalante, Rodrigo Calero Gil, Francisco Ayuga
Summary: Adaptation strategies are crucial to mitigate the impacts of climate change on social and environmental assets. Managed aquifer recharge (MAR) is a low-regret adaptive measure that not only solves social and environmental challenges, but also reduces the expected impacts of climate change.
Proceedings Paper
Education & Educational Research
A. Ramirez-Gomez, E. Ayuga, A. Garcia, J. M. Fuentes, F. Ayuga
14TH INTERNATIONAL TECHNOLOGY, EDUCATION AND DEVELOPMENT CONFERENCE (INTED2020)
(2020)
Article
Construction & Building Technology
Eutiquio Gallego, Jose Maria Fuentes, Alvaro Ramirez-Gomez, Francisco Ayuga
ADVANCES IN STRUCTURAL ENGINEERING
(2018)