Evaluation and consideration of local specimen material properties in lifetime prediction of short fiber-reinforced PA6T/6I

To exploit the full material potential of short fiber-reinforced PA6T/6I, specific component calculations including anisotropic material behavior is necessary. For this, different failure criteria and fatigue models are used to describe the behavior during a component service life. This paper deals with the determination and consideration of fiber orientations (FOs) for failure criteria and fatigue calculations. Therefore, a novel method to determine FO distributions across injection-molded plates is proposed. The developed method allows a forecast of FOs for different specimen extraction positions and angles on injection-molded plates by using only a few measured reference points. As a result, fatigue models can be calibrated with the strength values and the corresponding FO, calculated for fracture position. The performed tests show a non-negligible influence of failure positions, due to FO distributions along the specimens. So, the FO determination method delivers an improvement in strength values estimation.