This article describes a numerical study for the evaluation of the punching shear behavior of non-adherent prestressed flat slabs without shear reinforcement. Nonlinear three-dimensional models were used, along with the finite element method (FEA) through the ATENA software in order to validate the constitutive models adopted for concrete and steel. The numerical results were compared with the experimental results. The results revealed a good agreement among load capacity, deformations, and cracking panorama, as well as the relation between numerical and experimental failure loads. After validation, a parametric study was carried out to analyze the influence of tendon spacing, slab thickness, and column rectangularity in prestressed flat slabs. Finally, the results obtained in the numerical models in relation to the failure load were compared with the estimated values for the failure load according to the main normative predictions dealing with the flat slab system.

In conjunction with experimental studies, computational tools based on the Finite Element Method (FEA) have made it possible to analyze the phenomenon of punching and the influence of prestressing on the ultimate strength of flat slabs and thus understand this phenomenon through numerical simulations. In this study, experimental tests were simulated through three-dimensional analyses, using the constitutive models implemented in the ATENA 3D computer program, it was possible to validate the numerical results through the load-displacement and load-strain curves being compared with the experimental curves. The numerical results showed a difference in load capacity of less than 2% for the experimental models. After adequate calibration, a parametric study with eight models of prestressed slabs was implemented by varying the spacing and eccentricity of the prestressing tendons, punching resistance being evaluated with the new parameters. The punching resistant capacity of each model was also compared with the most current regulatory design predictions.