Nonlinear responses of various-sized reinforced concrete beams under uniformly distributed loading incorporating failure mechanism of circular beam

• The NSA is performed for various-sized RC beams under UDL. • The deflections of various beams are evaluated from the NSA and LSA. • The failure mechanism of circular beam is evaluated for the flexural plastic hinge. • The circular or rectangular beam shows better performance to compare the square beam. The nonlinear static analysis (NSA) of the circular beam by using flexural plastic hinges (i.e., placed at both supports and middle) under the uniformly distributed loading (UDL) is an innovative technique in this research. So, various-sized beams (i.e., circular, square, and rectangular) are used to evaluate the deflection under the UDL. The NSA in addition to the linear static analysis (LSA) is performed for two different approaches, such as (a) only reinforced concrete (RC) beams (i.e., no frame), and (b) integrated RC beams in various RC frames (i.e., 1, 3, and 5-storied). The numerical analysis is verified with the previous experimental study to obtain the difference in results between both studies of 2.4 %. The deflection rates of equivalent circular and rectangular beams are comparatively lower than the square beam. This happens due to the closer variations of depths compared to the square beam. The RC circular beam failed at the UDL of 126 kN/m, which is found in the failure mechanism. However, there is a scope to enhance this research in the future to conduct the experimental test.