Fatigue behaviour of vibration-welded joints made of Polyamide 6.6

The fatigue behaviour of welded plastic joints is of elementary significance for many plastic components which are exposed to vibratory loads in application. Within the framework of a research project, the South German Plastics Centre (SKZ) has therefore investigated the fatigue strength of vibration-welded Polyamide 6.6 with and without glass fibre reinforcement. Quasi-static tensile, vibration fatigue and dynamic load increase tests were performed for this purpose and short-time and long-time welding factors were established from these. On the basis of the results, it is possible to demon-strate that predictions of the fatigue strengths based on the short-time welding factors and characteristic values of the base materials would have been possible in all the considered cases.