Analysis of reinforced concrete beams with opening using incompatible mode elements and strut-and-ties model

Resumo

The need to reduce the execution time has led to the negligence in the process of compatibility project.
One of the consequences is the need to drill holes in beams for the passage of ducts and piping. This practice
occurs without criteria for analysis and structural design. Openings in beams performed without an accurate
analysis result in reduced strength considered in the design, instability and compromised safety. In the regions of
openings, usually called “Regions D”, the Bernoulli hypothesis becomes invalid and, therefore, the strut-and-ties
model associated with the finite element method has been used. This work proposes to analyze the distribution of
stresses in beams with opening using classical finite elements and enhanced with incompatible modes. Precise
results of internal efforts allow an adequate arrangement of reinforcements and fulfillment of safety in the ultimate
and service limit states. In order to validate the performance of the elements implemented for the analysis of
structures with discontinuities, the results obtained are compared with those found in the literature and calculated
using a commercial package. The results obtained attest to the quality of the implemented formulation.