Study On The Influence Of Mechanical Parameters Of Particles On Macroscopic Mechanical Properties Of Materials

In the study of artificial structural soil,the cementing material can be epoxy resin or cement.However,the cementation strength is too large,and the actual cementation is quite different.It is necessary to choose a suitable cementing material.In this paper,polyethylene glycol was used as a cementing material in different proportions with bentonite.Steel balls were used as matrix particles to make triaxial specimens.The relationship between different pore ratio,pore filling ratio and polyethylene glycol content on stress-strain was studied.The influence of the cementation on the macroscopic strength index was compared and analyzed.The following conclusions were drawn:The stress-strain relationship of the cemented specimens is strongly softened,which is related to the properties of the cementitious material of polyethylene glycol and its content in the sample.As the confining pressure increases,the peak strength of the stress and strain of the sample increases,and the polyethylene glycol content and the void ratio have a significant effect on the mechanical properties of the sample.When the pore filling ratio is 70%,the internal friction angle decreases first and then increases and then decreases as the polyethylene glycol content increases.When the pore filling ratio is 80%,the internal friction angle first decreases and then increases as the polyethylene glycol content increases.The sample having a pore filling ratio of 70%had a cohesive force smaller than that of the sample having a pore filling ratio of 80%.The influence of micromechanical parameters of gcomaterials on its macroscopic mechanical properties is the key to study the evolution mechanism and evolution law of mechanical properties of gcomatcrials.Based on the existing research results of particle cementation experiments,numerical simulation of PFC3D particle flow software is used.The relationship beetween the microscopic characteristics of the specimen failure and the macroscopic strength index was studied.The stress-strain relationship curve and the strength index were compared.At the same time,the force of the specimen under different loads was analyzed from the microscopic point of view,The evolution of chains,velocity fields and displacement fields.It was found that the contact force chain thickened as the strain increased.As the velocity field increases,the left middle and right middle particles tend to move outward,especially at low confining pressures.The displacement field has a similar law to the velocity field.Combined with the sensitivity analysis of parameters,the influence of mesoscopic parameters on macroscopic mechanical properties is discussed.The initial slope of the stress-strain relationship curve is found,that is,the elastic modulus is only affected by friction coefficient,loading rate,parallel bonding normal strength and parallel bonding.The effect of tangential strength.The parallel bond stiffness has little effect on the residual strength of the stress-strain curve.