Application Of Multiple Random Equivalent Plane Truss Model In Numerical Simulation Of Masonry Structures

Masonry is a kind of structure being widely used, especially the modern brick structure ,as it provides with the characteristics of beautiful shape, insulation, fire resistance ,durability and superior seismic performance. However, due to the complexity of the masonry itself as well as the dispersion of research results, people have not understood the whole process of stress and strain and cracking mechanism etc. of the masonry adequately and fully. The common numerical models of masonry on the mechanical properties are mostly based on the macroscopic , in which heterogeneous masonry materials with multi-phase is idealized as an homogeneous, continuous body for analysis.This processing based on average thinking can meet the requirement of engineering practice, but it ignores an important characteristic that non-uniformity of internal materials controls the cracking process of masonry, therefore it can not express the complexity of masonry cracking.At present, the international community has begun to take notice of the various advantages in the research of macroeconomic damage and cracking of masonry from the mesoscopic, this article ,which is just based on non-uniformity of masonry materials, adopts the Multiple Random Equivalent Truss Model established in literature[9] to study the mechanical problems from the meso-level.In this numerical model,different cells are endued with different mechanical parameters ,which comply with stochastic allocation,to describe the heterogeneous body of Masonry , simultaneously ,with the maximum tensile strain criterion utilized as damage threshold. On this basis, this model is used to simulate the whole failure process from crack initiation to failure for both masonry specimen under uniaxial compression and URM shear wall,numerical tests results match well from the deformation, cracking capacity and performance compared with the actual test results. On one hand,it proves the rationality and effectiveness of this model, on the other hand, through statistics of a large number of numerical tests, it provide some reference about the relevant parameters (such as mesoscopic cell size, mesh, strength threshold, and so on)for future use of this model.