With the advancement of computational techniques, numerous nonlinear constitutive laws have become available in finite element analysis software. While these models are well-suited to analyze plain and simple reinforced concrete structures, their applicability to prestressed structures, which constitute a significant…
With the advancement of computational techniques, numerous nonlinear constitutive laws have become available in finite element analysis software. While these models are well-suited to analyze plain and simple reinforced concrete structures, their applicability to prestressed structures, which constitute a significant portion of concrete constructions, requires validation. This study presents a finite element (FE) model composing a prestressed composite concrete girder, incorporating nonlinear stress-strain laws for the concrete, reinforcement steel and prestressing steel, as well as the concrete-to-concrete interfaces between prefabricated girder and cast-in-situ top-slab. To accurately capture the fracture process of the concrete, the total strain crack model is employed while the potential failure of the interface between the prefabricated girder and cast-in- situ top slab is modelled with two-dimensional line interface elements. The numerical model is validated using experimental results from precast continuous concrete inverted T-beams provided by TU Delft. A parametric study is subsequently conducted to assess the sensitivity of the numerical results to key assumptions in the nonlinear FE model. Specifically, the influence of adopting either a rotating or fixed crack model under high axial load is analyzed. Additionally, the effects of the shear retention factor and mesh size on the numerical response are investigated. While the numerically evaluated global load-displacement behavior shows good agreement with experimental results, it exhibits a sensitivity to the chosen mesh size and the specific smeared crack formulation. The findings also highlight the importance of considering the specific material properties and interface behavior in the modeling process to ensure reliable predictions of structural performance.