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Simulation of Complex 3D Behavior of Masonry Arch Systems
Masonry structures constitute a large portion of architectural heritage all around the world in the form of post-lintel systems; walls, arches, vaults and domes in buildings and masonry arch bridges. Since it is such a dominant construction material, achieving realistic numerical models of complex masonry structures is of particular interest to better understand their structural behavior and avoid unnecessary or poor interventions. This dissertation makes several contributions to the state of the art of modeling complex masonry arch systems. First, in discontinuum analysis commonly used contact models in tension (tension cut-off) does not capture the complete response of the material and also does not include mode-I fracture energy which leads to the underestimation of the capacity. In this context, present dissertation proposes new contact models to be incorporated into the discrete element method (DEM) to more accurately simulate the tensile softening in quasi-brittle materials, such as masonry, with an emphasis on fracture mechanism and post-peak response. As an important novel contribution, the proposed computational models successfully represent the complete (pre- and post- peak) material behavior and realistically replicate the cracking mechanism. Second, the discontinuum modeling strategy is extended to analyze the masonry arches and it is compared with different modeling strategies, namely limit state and sequential linear analysis. All numerical models are validated via experimental results and sensitivity analyses are performed on the mechanical properties of the material. Third, a novel 3D representation of masonry arch bridges is achieved using mixed discrete-continuum approach and it is validated with several experimental studies. With this modeling strategy, two main contributions are achieved; first, triggering mechanisms for the out of plane failure of spandrel walls are established; second, the influence of soil backfill on the behavior and strength of the bridges is better understood through a comprehensive parametric study. Transverse effects, damage patterns and collapse mechanisms are discussed under different types of loading considering different arch bridge models, representing common geometrical properties in the northwest Iberian Peninsula. The analysis demonstrates the severe capacity reduction due to spandrel wall failures and the importance of soil backfill in the behavior of these systems. These observations were, only possible by utilizing the proposed mixed numerical modeling strategy. Hence, a better understanding of masonry arch bridge behavior is accomplished by taking into account the soil-structure interaction problem.
Pulatsu, Bora, "Simulation of Complex 3D Behavior of Masonry Arch Systems" (2019). ETD collection for University of Nebraska - Lincoln. AAI13902180.