| The prediction accuracy of mechanical properties under fatigue loading in engineering plastics is increasingly important. In this study, the resistance to flexural and tensile cyclic loading of brittle and ductile materials was investigated respectively. The experimental results were then compared with theoretical prediction based on two existing residual strength degradation models, and conditions were examined to improve the model's applicability. The residual mechanical properties of the two materials were also evaluated and compared.;A correlation between parameters for a model and loading conditions was proposed. It allows the representation of fatigue life and possibly the residual strength with respect to stress ratio using a minimum number of experimental data. The observation of decreasing total energy absorbed by the specimen with increasing number of fatigue cycles in ductile material provided an insight in developing a fatigue model based on the energy criteria. |
