Micromechanical Research Of Adobe Masonry As Based On Bi-modularity Theory

Adobe masonry is largely used as construction material worldwide and the mechanical modelling of adobe structures is a key issue.In China's western region there are a lot of adobe masonry,and they are damaged in the earthquake due to the low bending,shear,bending strength of its own composition,and people often suffered heavy losses.The mesomechanical properties of adobe brick masonry units in four different bonded structures were studied in terms of micro-mechanics considering the different modulus of mortar and bricks with straw fibers.Analysis of mechanical properties of running bond RVE and simulation the compressive test and U-shaped wall Pseudo-static test of adobe masonry.Mainly carried out the following aspects:(1)Experimental tests showed bi-modularity(i.e.different Young modulus in compression and tension)for both mortar and bricks,so this feature of elastic behaviour was taken into account in micromodelling.(2)Two-dimensional micro-mechanics model of four different tectonic periodic units of adobe masonry by finite element method is established considering the bi-modular of the two-component composite and geometric boundary conditions.(3)Both classical elasticity and bi-modular theories were applied to bricks and mortar,adopting appropriate measures for shear modulus and calculating equivalent of the represent volume element(RVE)of running bond adobe masonry based on theory,and comparing with the material mechanics algorithm.(4)Separatly constructe the unit cell of running bond,considering the critical curves of brick and mortar,calculate the axial compressive strength of adobe masonry RVE,and draw the biaxial compressive failure envelope,and get the form of shear failure in finite element analysis.(5)Using the homogenization method,the equivalent of obtained RVE was used in the numerical simulation analysis of the axial compression test of adobe masonry with mortar mixed with straw fiber and no,and the U-shaped adobe walls based on the low-cycle and reverse horizontal loading test.The variety of deformation cloud reproducte failure mode of the test process,and compare with the difference in the test results.