Comparative Assessment of Deflections of Voided Reinforced Concrete Slabs: FEM Analysis and Manual Calculations

Abstract

This article presents a comprehensive comparative study of deflection voided reinforced concrete slabs, evaluating the results
obtained through Finite Element Method (FEM) analyses of various accuracy and manual calculations, specifically employing
the method of strips. Distinct methodologies used for analysis are: FEM analysis using SCIA Engineer, where voids in the slab
are accounted for by adjusting the modulus of elasticity and self-weight of concrete. The slab is modelled by using 2D slab
elements, allowing for efficient and relatively fast examination of structural behaviour and FEM analysis in ANSYS Workbench
Mechanical, where voids are modelled within a 3D solid representation of the entire slab. This approach should provide the
best representation of a real structure as it models all its elements with their respective physical attributes. Results of FEM
analyses would be compared not only to each other, but also with results of manual calculations, if possible. Calculations that
are going to be used are based on the method of strips, a traditional approach for analysing deflection of reinforced concrete
slabs. The comparative analysis encompasses calculations of deflection of voided reinforced concrete slabs with various
geometrical properties and boundary conditions. The findings aim to contribute to the engineering community by elucidating
the strengths, limitations, and trade-offs associated with each respective type of FEM analysis, as well as manual calculations,
when it comes to assessing the deflection of voided reinforced concrete slabs.