Research On Three-dimensional Finite Element Stochastic Simulation Model Of Rockfill Concret

Rock-filled concrete(RFC)is a bulk concrete dam building material obtained by filling the void of a rock skeleton with high-fluidity selfcompacting concrete(SCC),which has the advantages of low heat,high strength,and economy.Since the rock size is usually 300～1000mm,it is difficult for researchers to conduct tests on representative-size specimens,which seriously hinders the research process of mechanical properties and fracture mechanism of RFC.With the development of numerical simulation technology,it has become possible to simulate the overall properties of composite materials using component material properties by establishing a reasonable numerical simulation model.As a typical reinforced particle multiphase composite material,the RFC can be regarded as a three-phase composite material consisting of rock,SCC,and the interfacial transition zone between them on a fine scale.Combining the component material constitutive and the numerical simulation model of RFC,the limitation of specimen size can be effectively circumvented.The mechanical properties and fracture mechanism of RFC can be studied in a roundabout way.First,this paper presents a modeling method that can rapidly build a two-dimensional random aggregate model of RFC,which solves the problem of two-dimensional modeling of complex aggregate shape RFC with a high rockfill ratio.Second,this paper presents a modeling system that can combine numerical modeling methods and geometric modeling methods for the first time in the field of 3D random aggregate modeling,which can realize the rapid establishment of complex 3D models of RFC with a high rockfill ratio.Third,this paper proposes a modeling method for RFC random interface model by combining self-affine fractal theory,which can build RFC random interface model with different roughness and surface undulation degrees.Fourth,this paper uses Python to produce a plug-in for RFC random aggregate modeling in Abaqus software,significantly simplifying the modeling process.Finally,this paper proposes a numerical prediction method for RFC elastic modulus and compressive strength by combining the three-dimensional random aggregate model and component material constitutive.Through comparative analysis,we can conclude that:(1)when the rockfill ratio is more excellent than 60%,the modeling time of the RFC 2D modeling method is already one order of magnitude ahead of the traditional method;(2)the aggregate distribution obtained using the RFC 3D modeling method has uniform distribution characteristics;(3)when the rockfill ratio reaches 50%,the modeling time of the RFC 3D modeling method is only 1% of that of the traditional method;(4)The RFC random interface modeling method has the ability of parametric analysis;(5)The theoretical prediction method proposed by previous authors and the numerical prediction method in this paper have validity.