Periodic Modeling And Numerical Simulation Of High-Density Heterogeneous Polymer-Mineral Composites

Polymer-mineral composite is a new type of multi-phase composite material which is formed by vibration and curing,using mineral particles as aggregate,modified polymer as binder,and adding fine sand and other fillers.It has excellent thermal stability,damping performance,corrosion resistance and other characteristics,and is widely available for the machine tool beds manufacturing.With the development of computational materials science,many researchers have established meso-structural models of polymer-mineral composite materials by computer to study the effects of the distribution of different components and their density on the properties of the materials,and the optimization design of material microstructure is carried out.However,the generation algorithm of the high aggregate fraction model,namely the high-density meso-structure model,is still developing rapidly.There is still no ideal description model for the heterogeneous structure that exists widely in engineering practice.The modeling method so far is still difficult to apply to large components due to the limitation of modeling efficiency.In order to develop polymer-mineral composites with better performance,the modeling and simulation of their meso-structures has always been a hot topic in this research field.Based on the above-mentioned problems,the following research has been carried out in this paper:(1)An aggregate shrinkage-expansion-shrinkage method is proposed,and the mesostructure models of high-density polymer-mineral composites have been established.First,the aggregates are shrunk and put in,and then a temperature load is applied to the shrunk aggregates in the finite element software.Because of thermal expansion and cold contraction,the shrunk aggregates expand to produce plastic deformation and squeeze each other,and then elastically shrink.This method not only has high modeling efficiency and large aggregate area fraction,but also produces aggregate interlocking,which makes the material model closer to the actual structure.(2)An algorithm using a normal distribution function and a linear function to form a new composite function is proposed,and a structural model of the heterogeneous distribution of aggregates is constructed.According to this composite function,the aggregates are distributed in segments according to size gradation in one direction,and randomly and uniformly distributed in the other direction,thereby simulating the deliberately inhomogeneous or segregated structures in engineering practice.(3)Through the aggregate translation and cutting algorithm,the aggregate that intersects the model boundary and the corresponding aggregate at the opposite side boundary are overlapped to form a complete aggregate,and these aggregates are fixed in the subsequent expansion and shrinkage processes.Finally,the model with periodic boundary structure is formed.(4)Periodically replicate the above-mentioned periodic structural model,and finally obtain the structural model of the large-scale component,which greatly improves the modeling efficiency.Through finite element simulation,the influence of aggregates content,aggregates shape and other factors on the elastic modulus of the material are analyzed,and after avoiding the influence of aggregates shape on aggregates content,the elastic modulus and thermal expansion rate of the aggregates shape similar model are verified to change with the aggregate area.This study analyzes the thermodynamic properties of the material by constructing a periodic modeling and numerical simulation of high-density heterogeneous polymer-mineral composites.It is of great significance for material development,structural design,performance prediction,and performance analysis of components.