Comparison between simplified and refined models for calculating deflection in rc beams

Resumo

In this work, a comparative study of different simplified methods and refined models used for
calculating deflections in reinforced concrete (RC) beams, under service loads, is performed. Simplified methods
employed are the one recommended by Brazilian Code (ABNT NBR 6118), and the method recommended by the
European Code FIB. Two refined FE models are presented, one based on the NBR 6118 model and one based on
FIB model. These models use FE beam elements, and the material nonlinearities are considered by means of
moment-curvature diagrams. The models are implemented on the computational program named AVSer, limited
to analysis of beams up to yielding of reinforcing steel. Numerical results obtained by the different models are
compared with an experimentally tested beam. Some examples of simply supported RC beams under service loads,
by varying the beam geometry, the loading type, and the reinforcing ratio are analyzed. The results obtained by
the different models are compared. In the end of this work, differences between the models are pointed and
recommendations regarding the use of then are drawn.