Modelo para resistência de cisalhamento em vigas de concreto sem estribos

Abstract

The analysis of shear strength in concrete beams involves significant complexities and iteration between parameters. The development of models for the design and verification of the ultimate limit state of beams began in the 19th century with empirical, theoretical and numerical models such as the Ritter-Mörsch truss analogy and the modified compression field theory. However, the almost stochastic ratios of compressive strength of concrete, longitudinal reinforcement ratio, loading slenderness, transverse dimensions and coarse aggregate diameter add up to numerous difficulties in creating simple and easily applicable formulas. Thus, the present work aims to develop a model based on proportionality relations and the application of an iterative algorithm to optimize the values of an initial database of 220 beams (62 authors) that failure by shear and define a theoretical model that will be compared with a database of 510 beams (63 authors) and other methods of calculation of relevance. The proposed formula provided a coefficient of variation of 6.23%, being between 34.97% and 59.52% lower than the models analyzed. Thus, the results of the proposed method, when considering the experimental and theoretical relationship of the database, present all values within the appropriate safety range, allowing greater accuracy in defining the ultimate load of concrete beams without stirrups.