Development of numerical models for reinforced-concrete and stone masonry structures under seismic loading based on discrete cracks

Crack opening is one of the dominant causes of nonlinearity in brittle and quasi-brittle structures which leads to localized failure and stands out as a serious challenge in numerical modelling. The process of crack initiation starts at a micro-scale, and with progressive growth, micro-cracks coalesce into macro-cracks representing discontinuities in the material. Therefore, a realistic modelling of crack initiation and propagation is one of the key factors that affect the reliability of the model for analysing the structures, especially those subjected to earthquakes. Sophisticated numerical models based on time dependent and incremental dynamic analysis can play an important role in simulating the behaviour of such structures before and after collapse. This project aims to develop two nonlinear numerical models for incremental dynamic analysis of structures based on the model of discrete cracks. The first one will be a novel 3D model for reinforced concrete and stone masonry structures strengthened with clamps and bolts based on the combined finite discrete element method where the cracks are modelled through the contact elements implemented between finite elements. The model enables crack initiation and propagation, dynamic interaction of separate elements and monitoring of structural behaviour before and after the collapse. The second model will be based on the finite element method with embedded discontinuity and embedded reinforcement, which allows for crack initiation and propagation independent of finite element mesh and will be applied to reinforced concrete structures. The novel numerical models for reinforced concrete structures will be validated by available experimental research, while our own experiments are planned to be performed at shaking table for the validation of stone masonry structure model. Thereafter, the comparative analysis of the behaviour of real structures with both models will be conducted.