Samenvatting

In this study, two different numerical methods are used to model the structural behavior and failure mechanisms of unreinforced masonry (URM) walls under in-plane static loading using two simplified micro modelling approaches: The Discrete Finite Element Method (FDEM) and the Applied Element Method (AEM). The FDEM approach, which is implemented in LS-DYNA, models wall as separate deformable blocks interacting through point contacts, enabling detailed analysis of damage progression. The AEM approach, which is implemented in the Extreme Loading for Structures (ELS) software, treats wall elements as rigid parts connected by springs, providing a more computationally efficient and versatile solution. These two methods were compared in terms of accuracy, flexibility and computational cost. Performance of the application of the AEM and FDEM are evaluated with available experimental results of masonry wall under in-plane monotonic loading with micro modelling. Failure mechanism of the wall samples under different levels of axial load were evaluated with FDEM and AEM considering nonlinearity of bricks and brick–mortar bond. The impact of contact properties (FDEM) and spring properties (AEM) on the stiffness and in-plane load-bearing capacity of the wall were examined through a sensitivity analysis. The research used tornado diagrams to evaluate the results of the sensitivity analyses, offering insight into which material parameters should be prioritized in future data collection and testing considering two different numerical approaches. The analysis in the presented work revealed the strengths and weaknesses of each method, with the the AEM demonstrating lower computational cost and faster analysis times, while the FDEM provided detailed results due to its finer mesh. A sensitivity study was conducted to examine the impact of material properties on structural responses. It was found that changes in bond tensile strength, cohesion, and friction angle significantly influenced the progression of damage, leading to a shift between failure mechanisms. These findings highlight the importance of material parameter calibration for accurately predicting the behavior of masonry walls. For practical applications, the impact of variations in the material data on the numerical analysis results of masonry structures using the AEM and the FDEM are demonstrated.