Fatigue behavior and modeling of short fiber reinforced polymer composites: A literature review

Abstract Applications of short fiber reinforced polymer composites (SFRPCs) have been rapidly increasing and most of the components made of these materials are subjected to cyclic loading. Therefore, their fatigue behavior and modeling have been of much interest in recent years. This literature review presents a broad review of the many factors influencing cyclic deformation, fatigue behavior, and damage development in SFRPCs. These include microstructural related effects as well as effects related to loading condition and their service environment. Microstructural related effects include those related to fiber length, content and orientation, surface treatment, and failure mechanisms. Cyclic deformation and softening, viscous characteristics, and dissipative response used to characterize and model their fatigue damage behavior and accumulation are discussed. The effects of stress concentrations and their gradient on fatigue behavior are also discussed, due to their significant influence. The effects related to the loading condition include mean stress effects which may be accompanied by cyclic creep, variable amplitude loading, and multiaxial stress effects. Since fatigue behavior is substantially influenced by the testing frequency with self-heating as the primary consequence of increased frequency, this effect is also investigated. Environmental effects considered include the effects of moisture content and temperature, as well as thermo-mechanical fatigue behavior. The effect of welded joints in manufactured components made of SFRPCs and fatigue analysis and life estimation techniques used for such components are also included.