Analysis of Cracking in a Reinforced Concrete Beam

Numerical models describing crack formation and growth in reinforced concrete give reasonably good estimates of the bearing capacity and durability of an element of the structure without expensive full-scale tests. In this paper, a finite-element model is proposed to study the failure of a rectangular reinforced concrete beam subjected to four-point bending. The results of quasi-static simulation and the data obtained by taking into account inertial forces are compared. The feasibility of taking into account inertial forces is justified by assessing the contribution from kinetic energy (above 30%) at the instant of crack formation to the total mechanical energy of the system. Comparison of the experimentally obtained and calculated crack patterns is performed. It is shown that the mechanism of debonding between the reinforcement and concrete plays a key role in cracking.