Study On The Relationship Between Particle Interaction And Macro Mechanical Properties

Based on the discrete element method as the foundation, from the perspective of microscopic simulation triaxial test, established a relatively perfect triaxial test numerical simulation method.The microscopic mechanism of soil basic mechanics was studied by PFC2D numerical simulation software, the chain of granular materials in the process of shearing force and the change of displacement field, describes the microcosmic mechanism, and focuses on analyzing particle contact stiffness, particle microscopic mechanical parameters such as coefficient of friction and macro mechanical properties of relations under the different particle sizes and particle size arrangements.Through these work get the following main conclusions:(1) The peak intensity of the stress-strain curve increases with the increase of the friction coefficient. When the friction coefficient is small,the peak intensity increases rapidly with the increase of the friction coefficient. When the friction coefficient of the particle reaches a certain value, the peak intensity is no longer increased with the increase of the friction coefficient And the influence of the friction coefficient on the peak intensity increases with the increase of the particle size. With the increase of the friction coefficient, the loading speed is higher than that of the peak The larger the coefficient of friction, the larger the coefficient of friction, the greater the effect of the loading rate on the peak intensity. The peak intensity increases with the loading plate loading speed and linearly increases. With the increase of the particle size The effect of loading speed on the peak intensity curve increases gradually, indicating that the larger the particle size,the greater the effect of loading speed on the peak intensity.(2) The coefficient of friction corresponding to the big to small rows of samples has the greatest effect on the peak intensity, The impact curve is higher than the size of the big to big arrangement of the sample. While the big to big size of the sample arrangement curve is higher than the small to small size of the sample arrangement, The coefficient of friction corresponding to the small to big rows of samples has the least effect on the peak intensity(3) Increase ,with the increase of the peak strength as the contact stiffness, the beginning of the peak intensity increases with the increase of contact stiffness faster, when particles contact stiffness increases to 2.5 × 108N·m-1, after peak strength increases gradually slow;The bigger particle size, particle the greater the influence of contact stiffness on the peak strength.Under different size of particle size, the influence of contact stiffness on the peak strength is different,but the overall trend.(4) The contact stiffness of the big to small rows of samples has the greatest influence on the peak intensity, The impact curve is higher than the size of the big to big sample, While the big to big size of the sample arrangement curve is higher than the small to small size of the sample arrangement, The contact stiffness of the small to big rows of samples has the least influence on the peak intensity.