The need for conservation management in European 19th century urban housing

The prediction of the dynamic response of Unreinforced Masonry Structures (URMS) is a very complex task, since it is governed by material degradation and cyclic hysteric behaviour. Procedures based on nonlinear static analyses have been proposed for the seismic assessment of URMS, without properly considering hysteretic energy dissipation during the dynamic response. Even though dynamic nonlinear analyses provide satisfactory simulations of the seismic response, its application requires considerable computational effort and high user expertise for the accurate definition of the material properties, making it unsuitable for practical applications. However, simplified macro-element strategies, capable of simulating in-plane and outof-plane nonlinear responses, could represent a satisfactory engineering solution in the dynamic context. In this study the nonlinear static and dynamic in-plane behaviour of URMS was assessed by means of plane discrete models. The preliminary numerical investigation evidenced the need to define suitable hysteric constitutive laws for reliable nonlinear dynamic analyses of URMS.(undefined

Computational strategies for masonry structures

Civil Engineering and Geoscience

A 3D discrete macro-element for modelling the out-of-plane behaviour of infilled frame structures

A high percentage of new and existing framed buildings (either in concrete or steel) are built with unreinforced masonry infilled walls leading to the structural typology known as Infilled Frame Structures (IFS). In these structures, the masonry infills are built after the construction of the main structural frame and are considered as non-structural elements. For this reason, the contribution of unreinforced masonry infills is generally neglected, in the structural analysis of IFS, leading to inaccuracies in the prediction of their seismic nonlinear response. In this paper a three-dimensional discrete element method, able to simulate the complex interactions, in-plane and out-of-plane, in IFS is presented. In the proposed approach, the infill wall is modelled by means of an original spatial discrete element previously introduced for the analysis of UnReinforced Masonry (URM) Structures. Since the attention is focused on the behaviour of the masonry infills, the frame elements have been assumed as linear elastic beams interacting with the macro-elements through plane nonlinear interfaces. In the paper, after a theoretical description of the proposed approach, several experimental–numerical comparisons are provided for investigating the out-plane behaviour of infilled frames. The achieved results demonstrate the accuracy and the significant potential of using the proposed approach for the non-linear analysis of IFS under different loading conditions.(undefined)info:eu-repo/semantics/publishedVersio