A general model for analysing response of slender masonry structures under multi-component earthquake excitations

In this paper, a numerical method is presented to perform non-linear dynamic analysis of coupled transverse and longitudinal oscillations of masonry beams with different constrains when subjected to any dynamic loading type, including vertical and transverse motion imposed at their support. In developing the model, a non-linear constitutive equation giving stress characteristics as a function of strain ones, for materials with no tensile strength and limited compressive strength, has been used. The model allows to analyse dynamic behaviour of masonry slender structures with primarily flexural behaviour - such as towers - under multi-component earthquake excitations: it seems a useful model since it requires short computational time, while accounting for the material non-linear behaviour. Results from a case study evidence the difference in dynamic response with respect to responses obtained both from a linear elastic analysis and from a simpler non-linear model, where no allowance for a limited compressive strength was made. Subsequently, preliminary results on dynamic response of slender towers under real input ground motion evidence the ability of the model to supply information which may be used to evaluate indices of global and local structural damage.