Author(s)

A. Taliercio

Abstract

The numerical modelling of the time evolution of stresses and strains in brickwork under sustained loads is dealt with, within the framework of linear viscoelasticity. Finite element analyses were carried out, using three different masonry models: a simplified 2D layered model, and two 3D models (one for header bond masonry; one for Flemish bond masonry). The creep behaviour of the component materials (bricks and mortar) was defined according to experimental data available in the literature. These results were best fitted by Prony series, and the obtained creep laws were employed to carry out FE analyses of the masonry walls with different textures. Owing to the different mechanical response of the components to sustained loads, the stress and strain distribution in the wall changes in time and differs from that at the beginning of the loading process. The different behaviour of the two considered brick patterns is pointed out. The possibility of applying the simplified layered model instead of refined 3D models to predict the time evolution of stresses and strains is discussed. Keywords: masonry, creep, linear viscoelasticity, header bond, Flemish bond. 1 Introduction The application of sustained loads on masonry structural elements induces creep phenomena, accompanied by a redistribution of stresses and strains. Under service loads, strains usually stabilize after a given time. On the contrary, damage effects (i.e. microcracks) induced by heavy loads can coalesce and grow, bringing the structural element to failure. In the former case, anyway, the longterm stress and strain state can differ, even considerably, from the short-term one.

Keywords

masonry, creep, linear viscoelasticity, header bond, Flemish bond