Dynamic analysis of slender towers made of no-tension material with limited compressive strength

摘要

This paper deals with a simplified non-linear model of continuous cantilever beams that, while it can make it easier to represent the dynamic response of masonry columns and slender structures with simple geometry and flexural behaviour, is able to account for the main mechanical characteristics of the material. A non-linear elastic constitutive law is defined in terms of generalized stress and strain, assuming the material has no resistance to tension and has limited compressive strength, which has been formulated in previous work for rectangular cross-section beams and generalized, in the ongoing work, to the case of hollow rectangular sections, in order to study the dynamic behaviour of various types of towers, bell towers and similar structures. Therefore, this relationship has been used to develop a numerical method that allows one to analyse the non-linear dynamic behaviour of masonry isolated towers under multi-component earthquake excitations or different dynamic loads. Some numerical examples are presented in order to show: (ⅰ) the difference in prediction of dynamic response obtained by means of the developed model with respect to the linear elastic one, (ⅱ) the influence of the material's compressive strength on non-linear response, (ⅲ) information provided by the model on damage spread in masonry structures.