The expressions provided by codes of practice for shear and punching strength of reinforced concrete members are based on simplified mechanical models where complex multiscale phenomena, such as aggregate interlocking, steel-concrete interaction and concrete crushing, are taken into account by means of empirical coefficients. Hence, their reliability outside the range of the experimental results over which they are calibrated is often questionable. Refinement of these models requires accurate descriptions of the multi-phase material microstructure through a meso-mechanical approach in which aggregates and matrix are explicitly represented. Moreover, the information at the meso-scale has to be transferred to the engineering scale by means of a multi-scale computational approach.The innovative methodology of the present proposal is to create a synergy between the semi-empirical approach behind the development of standards and the most advanced computational mechanics one. The main goals are:- Develop a 3D meso-scale finite element model for the analysis of quasi-static and dynamic fracture in multi-phase solid materials.- Provide a multi-scale approach to incorporate meso-structural details into the continuum scale.- Contribute to the development of an open-source code.- Simulate experimental results on shear and punching failures available in the literature.- Apply the numerical approach to better quantify the empirical coefficients entering the expressions given by the standards.Particular attention is devoted to dynamic effects consequent to extreme loading conditions (impacts, explosions, seismic loads).Within this project, the fellow will acquire new competencies and skills in the fields of non-linear modelling, dynamic fracture, multi-scale modelling, high performance computing, design concepts and strategies. This will strengthen his multidisciplinary academic profile in fracture mechanics, structural modelling and design, and computational mechanics.