Nonlinear finite element modeling of reinforced concrete shear walls: from validation to innovation

This study presents a numerical investigation on reinforced concrete shear walls using multi-layer shell element (MLSE) formulation within the FEMIX software, considering variations in material properties and geometric configurations. Analysed typologies include in-plane shear walls, U-shaped cast-in-place walls, steel fibre-reinforced concrete (SFRC) walls, and precast walls with bolted connections. The nonlinear hysteretic response is evaluated in terms of load-displacement behaviour, initial stiffness, ductility, and ultimate capacity. To assess the predictive performance of the MLSE model, a quantitative Accuracy Score (AS) framework is introduced comparing numerical results with experimental data and alternative modelling approaches. The results demonstrate that the MLSE approach provides a robust and computationally efficient framework, accurately capturing global strength, stiffness degradation, and ductility, with predictive performance comparable to continuous-based solid finite element formulations. In contrast, simplified macro-models tend to underestimate post-yield deformation and ductility, particularly in systems governed by complex interaction mechanisms. Using the validated MLSE methodology, an innovative core wall system is proposed, composed of prefabricated SFRC panels with embedded steel profiles and shear connectors. The novelty of the study lies in integrating the MLSE formulation with the Global Resistance Method, establishing a computationally efficient and engineering-oriented framework for assessing the nonlinear behaviour of complex wall systems.