Size Effect Studies on Plain and Reinforced Concrete Beams by Extended Finite Element

In this study, a numerical survey on size effect on failure stress in reinforced concrete beams and plain concrete beams with initial crack under gravity loading has been investigated. Abaqus software was used for this purpose. Behavior of cracks was simulated by cohesive crack model (CCM). Since the mechanical operation of structures is in clear dependent to growth of cracks, to investigate the significant effect of cracks on the behavior of concrete beams, a parametric study on geometrically scaled beams with different dimensions, under a three-point bending test with different sizes of initial crack was done. In order to validate the analytical method, the available test results were used. The size effect of the beam on failure stress in concrete beams and reinforced concrete beams was investigated. Moreover, the effect of beam size on the stresses that occurs in reinforcing bars, were studied. According to this study, the effect of size on the failure stress in the plain concrete beams and stresses occurs in rears in reinforced concrete beams is clearly evident, but has a little impact on the failure stress in reinforced concrete beams modeled in this study.

Keywords:

size effect , extended finite element , Rc beams , plain concrete beams , cohesive crack model , fracture mechanics , quasi brittle materials