Introduction: In The Last Few Decades, Increasing Demand For High

Introduction: In the last few decades, increasing demand for high strength-to-weight ratio materials for construction industry and advanced applications like aerospace engineering has led to the increasing utilization of fibrereinforced polymeric composites. In the majority of engineering applications vibration and other fluctuating loads are mostly inevitable; in the other hand, the mechanical fatigue is considered to be the most common type of failure of structural components; thus for an appropriate and efficient material selection, dynamic properties of materials especially fatigue life, strength and mechanisms should be considered. Fatigue of FRP composites is a more complicated phenomena (comparing to the metals fatigue) due to the fact that Different damage mechanism and degradation can contribute to the fatigue failure of FRP composites e.g. fibre fracture, matrix cracking, fibre buckling and their interactions. Lots of parameters can affect fatigue behaviour of FRP composites including Type of fibre reinforcement, type of resin, fibre volume fraction, and interfacial strength. As well as fatigue usual parameters like loads magnitude and frequency, specimen shape and R ratio. However lots of research has been done in order to control damage initiation and damage evolution in The aim of this report is to review design and selection of polymer matrix composites in fatigue performance point of view so first different mechanisms behind fatigue of these materials will be discussed and then two situations where fatigue of this type of composites is a critical issue will be considered: Wind turbine blades and helicopter rotor blades, which correspond to a different fatigue conditions.