Instability and failure of particulate materials caused by rolling of non-spherical particles
In particulate materials under compression at the peak load the accumulated damage allows particle rolling.For non-spherical particles the moment equilibrium dictates that further increase in displacement requires reduced shear stress producing an effect of apparent negative stiffness; its value depends upon the magnitude of the compressive stress.Dilatancy produced by rolling particles reduces the value negative stiffness,while the contraction phase causes immediate instability.Material with rolling particles is macroscopically modelled as a matrix containing inclusions with negative shear modulus.When the concentration of negative stiffness inclusions is low,the effective shear modulus is positive and the material is stable.When the concentration reaches a critical level the effective shear modulus abruptly becomes negative and the material loses stability.Furthermore,there exists a special value of negative shear modulus of inclusions (and hence the magnitude of compressive stress) when the critical concentration becomes zero,such that the first rolling particle induces the global instability.
Rolling particles Negative shear modulus Effective shear modulus Critical concentration Dilation
Elena Pasternak Arcady V. Dyskin
School of Mechanical and Chemical Engineering,University of Western Australia,6009,Australia School of,Civil and Resource Engineering University of Western Australia,6009,Australia
国际会议
北京
英文
1-10
2013-06-16（万方平台首次上网日期，不代表论文的发表时间）