Fatigue design of highly loaded short-glass-fibre reinforced polyamide parts in engine compartments

The fatigue strength behaviour of a short-glass-fibre reinforced polyamide PA66-GF35 was investigated in detail. The consideration of influencing variables like notches, fibre orientation, temperature, mean-stress and spectrum loading enable the fatigue design of high loaded plastic parts in engine compartments. A design method was developed which is based on FE calculation of the maximum local stress, the appertaining stress gradient and the highly stressed material volume. The method was verified successfully by the example of a fuel rail.