The increase in the use of flat slabs and the need of the openings for the passage of installations, such as hydraulic and electrical, which significantly reduces the punching shear resistance capacity of the slab, makes the understanding of the influence of openings in this type of structure extremely necessary. The influence in the structural behaviour of flat slabs with openings at different distances from the column was investigated through five square slabs (1,800 mm x 1,800 mm x 130 mm) supported on square columns (150 mm x 150 mm) tested until failure. The results obtained experimentally were compared with results available in the literature, as well as with responses predicted from the normative instructions. The results confirm high stresses concentration in the region between the column and the opening and that opening situated at 3d from the column have no influence on the failure load for the tested slabs.

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.

Increasing the shear reinforcement ratio (ρ_w) can help meet architectural and structural requirements but often results in less reliable punching strength estimates from design codes. Nonlinear finite element analysis (NLFEA) has the potential to support a thorough assessment of the punching strength of slabs with shear studs, yet accurately modelling the interaction between concrete and transverse steel to capture the strength provided by shear rebars is challenging while using user-friendly software. This paper explores methodologies to assess the punching strength of slabs with double-headed studs with a commercial NLFEA program. Experimental tests were used to define the input parameters for the concrete’s nonlinear behaviour and to evaluate modelling approaches for shear studs, resulting in two strategies applied to slabs with varying ρ_w. NLFEA provided accurate punching strength estimates, consistently reproducing slabs’ rotations, crack patterns, and flexural strains. However, discrepancies in shear rebar strains highlight the challenges of using NLFEA to assess the response of slabs with shear reinforcement. Moreover, NLFE and experimental strengths were compared to estimates using the fib Model Code 2010 with levels of approximation (LoA) II, III, and IV, showing that, for the selected tests, increasing complexity in LoA IV did not consistently improve strength estimate accuracy.

Structural masonry is defined as masonry admitted as part of the structure. Prisms are simplified samples of masonry and are widely used in quality control of this type of structural system. They are particularly important because they allow evaluating the compressive strength of the masonry used in the construction and, thus, guarantee that the project is executed according to the designer's specifications [¹ 1 Brazilian Association of Technical Standards, ABNT NBR 16868-1 – Structural Masonry – Part 1: Project, 2020. ]–[³ 3 J. A. Thamboo and M. Dhanasekar, “Correlation between the performance of solid masonry prisms and wallettes under compression,” J. Build. Eng., vol. 22, pp. 429–438, 2019, http://dx.doi.org/10.1016/j.jobe.2019.01.007. http://dx.doi.org/10.1016/j.jobe.2019.01... ]. In Brazil, the monitoring of these parameters is carried out through tests specified in ABNT NBR 16868-3 [⁴ 4 Brazilian Association of Technical Standards, ABNT NBR 16868-3 – Structural Masonry – Part 3: Test Methods, 2020. ], which indicates that the characteristic compressive strength obtained through tests must be equal to or greater than that specified by the designer. Prisms and the quality control performance tests are essential to guarantee the safety and effectiveness of constructions [⁵ 5 G. H. Nalon et al., “Review of recent progress on the compressive behavior of masonry prisms,” Constr. Build. Mater., vol. 320, pp. 126181, 2022, http://dx.doi.org/10.1016/j.conbuildmat.2021.126181. http://dx.doi.org/10.1016/j.conbuildmat.... ].

This study presents a hybrid approach that combines the Finite Element Method (FEM) and Artificial Neural Networks (ANNs) to predict the ultimate punching shear capacity of flat slabs supported by interior columns. FEM models were first developed and validated against experimental results to simulate slab behavior. These models were then used to generate a numerical dataset containing 1000 entries with varying geometric and mechanical parameters. Based on this dataset, 600 ANN architectures were trained and evaluated, from which three were selected for their high predictive performance (R² > 0.99, MAE < 8 kN). A sensitivity analysis on network hyperparameters and dataset size revealed that 500–750 samples are sufficient for accurate ANN training. Finally, the selected ANN–FEM models were tested against 20 experimental cases and compared to predictions from ACI 318, Eurocode 2, and NBR 6118. While the design codes showed significant underestimations (up to 95%), the ANN and FEM models resulted in mean percentage errors of 11.6% and 10.1%, respectively. These findings demonstrate that the proposed hybrid approach provides an accurate, efficient, and practical alternative for predicting punching shear capacity in structural design.