Analysis of Shear Damage Accumulation of Reinforced Concrete Beams under Repetitive Fatigue Loadings
B. H. Oh and S. H. Han
Appears on pages(s):
beam; concrete; crack (diagonal); fatigue; shear
Considerable research has been done to study the fatigue behavior of concrete structures. Plain concrete and reinforced concrete, when subjected to repeated loads, may exhibit excessive cracking and may eventually fail after a certain number of load repetitions. A quantitative analysis of cyclic behavior of reinforced concrete beams is important to understand safety and serviceability problems under repeated shear critical loading conditions. In this study, a quantitative analysis method for the damage process of reinforced concrete beams under repeated shear loading is proposed. It is based on the progressively increasing strain and stiffness reduction. The analysis technique is mainly based on the modified compression field theory and scalar damage concept, which describes the strain and stress configuration in the shear zone by considering the 2-dimensional effect. It expresses the degradation of principal compressive strut by cyclic strain increment, secant modulus decrement, and modifying the parabolic stress strain relationship. The analysis f the response of reinforced concrete beams under repeated shear-flexure loading has been carried out and compared with the experimental results. The present theory may efficiently be used to evaluate the deflection and strain accumulation under repeated loads.