A Non-Linear Fatigue Damage Model for Concrete in Tension

Although concrete is used primarily because of its properties under compressive loading, a knowledge of its tensile behavior is essential in situations in which cracking, and the resulting change in stiffness, are critical for the service and ultimate load behavior of a structure. One important aspect of the tensile behavior of concrete is its performance under cyclic loading. The majority of past studies on the tensile fatigue performance of concrete have focused on the behavior under constant amplitude loads. However, in recent years, the effect of variable amplitude loading has also been emphasized. In this paper a model is presented for fatigue damage accumulation for concrete subjected to nonconstant tensile cyclic loads. The model is based on the concepts of Continuum Damage Mechanics and is able to account for the nonlinear propagation and accumulation of fatigue damage. Calibration of the model is done using existing experimental data, and its validity is checked against recently published tests.