Finite Element Macro-modeling of a Historical Masonry Building : Influence of Isotropic vs Anisotropic Plastic Material Model Assumption in Static Analysis

Sammanfattning: In this study, a macro-modeling strategy is implemented in a bearing wall with arch openings in an existing historical masonry building. This is to investigate what differences and similarities can be observed from the assumption of an orthotropic versus an isotropic constitutive material model. A static analysis is performed in the finite element analysis program RFEM6 where deformations, stresses, and strains are evaluated up to ultimate vertical and lateral loading. A validation of the orthotropic plastic material model in the utilized program is conducted by comparison with experimental shear wall tests from the literature. Results from the static analysis are compared to ultimate limit state calculations from the governing Eurocode standard SS-EN 1996-1-1. It is observed that an orthotropic material assumption is generally more conservative in deformation and strain assessment in this case, while stress distributions correspond well between all assumptions. Furthermore, it is noted that great attention should be paid to mortar strength assumption if the properties of existing mortar are not known as this can have a large impact on results. Two out of three material models satisfy the Eurocode 6 standard criteria when subjected to vertical and lateral loading. Results from the shear loading are found to not verify the RFEM results due to a large disagreement between analytical and numerical results.