Analysis On Depth Of Crack And Stress Of Steel Bar In Reinforced Concrete Beam After Cracking

As is known to all, crack is a commonly- occurring illnesses of concrete structure. This paper makes researches on crack propagation and mechanical performance after cracking of reinforced concrete beam.Firstly, this paper proposes a new way to simulate concrete cracking in which randomness of concrete is considered. Real concrete strength distribution is simulated by the principle of probability and statistics, and the cracks are simulated by deleting some elements in these models. Therefore, this simulation method about weak area and cracking process of concrete structure are more reasonable and scientific.Secondly, stress of steel bar is obtained by post-processing technology in this paper. And on this basis, cracks with different widths, depths and locations are simulated to get the steel bar stress regularities of maximum stress and distribution. The result of simulation shows that:the stress of steel bar is affected by cracks only on the section where they appeared. The crack width has a negligible effect on the stress of steel bar in reinforced concrete beam and the crack depth affects the stress of steel bar significantly. The crack location has quite effect on stress of steel bar and the cracks can change the location where the maximum stress appeared in beam.At last, from the practical case of five reinforced concrete beam, the comparison between measured data and simulation results shows that the new method that considers randomness of concrete strength is effective on crack depth simulation. At the same time, by the aforementioned method, the security assessment of reinforced concrete beam is made based on the stress of steel bar at different load levels.