Study On Homogenization Process Of Masonry And Its Applications Using Numerical Simulation

The homogenization theory has advantage of discreet element andmacro-continuum model, which is important to study on mechanical model. Accordingto homogenization theory, Numerical simulation method of homogenization processof masonry is analysed. Equivalent material properties of RVE is obtained and theresearch of influence factors of which is done. Based on the equivalent parameters ofthe RVE, macro-continuum model of masonry wall is modeled and analysed.Basic assumptions and applicable conditions of homogenization approach areoverviewed and implementation methods of homogenization technique in Finiteelement are elaborated. With describing the concept of the representative volumeelement which is the object of study on homogenization approach and proving thatRVE can represent the overall mechanical properties of masonry, the contentmentioned above makes the concept of the RVE more clear, at the same tine，providetheoretical basis for this paper.Considering strain state on each side of the RVE, periodic boundary conditions isestablished, which constraint equation in finite element analysis is discussed and setup. Python subroutine is developed and with which the periodic boundary conditionscan be generated automatically when creating finite element model. The work of thispaper may offer some reference and gist for research on finite element model of RVEin pre-processing.With ABAQUS Finite element software and the subroutine of periodic boundaryconditions, three-dimensional finite element model is developed, and the numeriallysimulations of RVE is derived in order to analyse RVE’s equivalent stress state ofuniaxial，blaxial，shear-compression. Strength envelope of the RVE obtained in thisprocess can explain the failure of masonry, which can be defined by there differentmodes,namely, compression failure, tensile failure and shear failure. Acording toorthotropic elastic matrix, equivalent elastic modulus, shear modulus, and Poisson’sratio of the RVE is obtained. And different directions of loading, brick species andcomponent selection modes can affect mechanical properties of the RVE.In order to create the macroscopic damage model of RVE, damage factor whosevalue is calculated with elastic residual energy equivalence principle is introduced.Based on ABAQUS software, macro-continuum model of masonry is created.acording to equivalent properties of the RVE, quasi static analysis of autoclaved lime_stone sand brick masonry wall is carried out and hysteresis curve is obtained，showing energy dissipation capacity of the masonry wall. And we can see thatdistributions of the plastic tensile strain in the model is roughly identical with theposition of wall cracks in the experiment. Ductility coefficient of the masonry wall inthe model is a little greater than that in the experiment. By comparing the simulationanalysis results and experiment results, it shows that macro-continuum model basedon homogenization approach not only have the advantage of free grid division but alsowell simulate the mechanical property of masonry wall.