Abstract
The traditional methodology for designing slab systems typically commences with manual calculations of support and span moments based on linear elastic theory. These moments are subsequently redistributed according to the adopted design framework to achieve an optimal balance between structural performance and cost efficiency. The reinforcement areas are then computed for each region of moment distribution, with supplementary reinforcement introduced to control cracking and mitigate punching shear effects.
Contemporary computer-aided design approaches, employing finite element (FE) analysis, determine internal forces at the elemental level under the same linear elastic assumptions. The resulting reinforcement requirements are provided for each mesh element. Accurate control of internal force magnitudes, particularly bending moments is essential when employing linear elastic FE analyses. The quality of the FE mesh is a critical factor, requiring attention to parameters such as element shape, aspect ratio, and the relative size of adjacent elements. Mesh-related irregularities may also arise in slabs supported by interior, edge, or corner columns, as well as in areas containing openings. In the case study below, the design sequence of reinforced concrete slabs using the SAP2000 program (FEM analysis) is described to meet the requirements of flexural behavior, punching shear capacity and overall deformation performance according to the Eurocodes.