The discrete element method is used to simulate specimens under three different loading conditions(conventional triaxial compression,plane strain,and direct shear)with different initial conditions to explore the und...The discrete element method is used to simulate specimens under three different loading conditions(conventional triaxial compression,plane strain,and direct shear)with different initial conditions to explore the underlying mechanics of the specimen deformation from a microscale perspective.Deformations of specimens with different initial void ratios at different confining stresses under different loading conditions are studied.Results show that the discrete element models successfully capture the specimen deformation and the strain localization.Particle behaviors including particle rotation and displacement and the mesoscale void ratio distributions are used to explain the strain localization and specimen deformation.It is found that the loading condition is one of the most important factors controlling the specimen deformation mode.Microscale behavior of the granular soil is the driving mechanics of the macroscale deformation of the granular assembly.展开更多
This paper examines the assumptions of the Rational Man (RM) model familiar in social and political studies. It is observed that the model is too restrictive in its explaining events and behavior in social and polit...This paper examines the assumptions of the Rational Man (RM) model familiar in social and political studies. It is observed that the model is too restrictive in its explaining events and behavior in social and political situations. It is suggested that the assumptions of RM model should be relaxed using the familiar methods and techniques of elementary formal logic. The concept of relevance is then introduced to take account of a "weaker" formal requirement in an attempt to explain events and processes in human action and/or behavior. The concept of "justification by reasons" is then introduced as a necessary though not sufficient requirement of explaining events and processes in social and political studies展开更多
基金The National Natural Science Foundation of China(No.51079030)
文摘The discrete element method is used to simulate specimens under three different loading conditions(conventional triaxial compression,plane strain,and direct shear)with different initial conditions to explore the underlying mechanics of the specimen deformation from a microscale perspective.Deformations of specimens with different initial void ratios at different confining stresses under different loading conditions are studied.Results show that the discrete element models successfully capture the specimen deformation and the strain localization.Particle behaviors including particle rotation and displacement and the mesoscale void ratio distributions are used to explain the strain localization and specimen deformation.It is found that the loading condition is one of the most important factors controlling the specimen deformation mode.Microscale behavior of the granular soil is the driving mechanics of the macroscale deformation of the granular assembly.
文摘This paper examines the assumptions of the Rational Man (RM) model familiar in social and political studies. It is observed that the model is too restrictive in its explaining events and behavior in social and political situations. It is suggested that the assumptions of RM model should be relaxed using the familiar methods and techniques of elementary formal logic. The concept of relevance is then introduced to take account of a "weaker" formal requirement in an attempt to explain events and processes in human action and/or behavior. The concept of "justification by reasons" is then introduced as a necessary though not sufficient requirement of explaining events and processes in social and political studies