Evolution of Damage Indicators under Cyclic Loading of a Composite Plate with a Hole

A new experimental method has been developed that provides a quantitative description of the evolution of damage indicators under cyclic loading of composite samples with stress concentrators. Damage parameters are defined as the deformation response to the application of an artificial cut of a given length, which extends from the contour of the central through hole in a flat rectangular sample under constant external load. Based on the test results of eight samples, the current values of damage indicators at various stages of fatigue loading were obtained. These data reveal the dependence of the required parameters on the number of loading cycles. On this basis, a damage accumulation function was constructed for the considered range of cycles. It has been established that this function refers to the first stage of the process under study. The results obtained are a necessary basis for planning further experiments.