Cosserat finite elements for 3D static and dynamic analyses of homogenized running bond masonry structures

A displacement-based Finite Element Method dynamic formulation for continuum modelling of masonry structure is herein presented and validated within the framework of the Cosserat continuum theory. For numerical validation purposes, a particular homogenized orthotropic Cosserat constitutive model has been taken into account for running-bond masonry brickworks (Stefanou, Sulem, & Vardoulakis, 2008). Nevertheless, the formulation is quite general and allows the implementation of various materials with microstructure. The model has been previously implemented such User Element in the commercial code ABAQUS (Abaqus 6.10 - Documentation, 2011) and has been used in static conditions by Stefanou, Sulem & Vardoulakis (2007). The formulation is herein extensively tested and extended to modal analysis, allowing the user to conduct dynamic analyses in linear elastic regime. It is shown how a Cosserat formulation has interesting computational properties with respect to a classical continuum-based formulation and can provide suitable results when applied to masonry structures, against the use of more expensive and complex heterogeneous models.

Un codice agli Elementi Finiti di Cosserat é implementato per permettere di modellizzare il comportamento dinamico e spaziale di strutture murarie. Il codice é validato in condizioni statiche e dinamiche e le performance della formulazione alla Cosserat sono studiate. Alcune applicazioni sulle strutture murarie sono infine fornite al fine di dimostrare le capacità dell'elemento finito e di alcune leggi costitutive d'omogenizzazione alla Cosserat nella riproduzione del comportamento meccanico di suddette strutture.