On the residual strength of long-fibre reinforced thermoplastics after fatigue damage
It is undeniable that mechanical properties, such as stiffness or residual strength of composites, are adversely affected by fatigue damage. In order to quantify and predict this damage influence, Witzgall and Wartzack developed a calculation approach for the subgroup of short-fibre-reinforced thermoplastics. To expand this approach to long-fibre-reinforced thermoplastics, the decrease in mechanical properties is investigated in this paper using PP LGF30. The novelty of the contribution lies in the continuous modelling of fatigue behaviour for arbitrary oriented samples of long-fibre-reinforced thermoplastics and also in the prediction of its residual strength depending on previously induced fatigue damage. A decrease in the residual strength of up to about 35% could be recorded.