Computer Simulation of Reinforced Concrete Beams Taken Into Account of Defects and Damage

The article examines the influence of defects and damage on the stress-strain state, strength, crack resistance and rigidity of reinforced concrete beams. Based on computer modeling in the ANSYS and Lira-SAPR software packages, a multifactor numerical experiment was carried out. The following influencing factors are considered: the depth and length of destruction of the protective layer of concrete in the tensile zone, concrete spalling in the compressed zone, a decrease in the area of reinforcement, a local decrease in the strength of concrete, the presence of normal cracks at different percentages of longitudinal reinforcement, delamination of concrete flanges, a change in the class of concrete. The computer model was verified by comparing the results obtained numerically with data from full-scale testing of similar beams. For each factor, the impact on the strength, crack resistance and rigidity of reinforced concrete beams was assessed. It has been established that the rigidity and strength of beams with a lower percentage of reinforcement are more sensitive to initial defects in the form of normal cracks in the middle of the span. The depth and length of destruction of the protective layer of concrete in the tensile zone has practically no effect on the studied parameters. A change in the strength characteristics of concrete to a depth of 20 mm along the perimeter of the section (during concrete corrosion) significantly affects the cracking load, while the strength and rigidity decreases slightly.