Pin-loaded tensile behavior and failure analysis of CF/PEKK composites under extreme temperature

This study investigated pinned-joint bearing strengths and failure behaviors of carbon-fiber-reinforced polyetherketoneketone (CF/PEKK) composites at different temperatures, with varying the width-to-hole diameter (W/D) and edge distance-to-hole diameter (E/D) ratios. Increasing the W/D ratio substantially amplified the pin load capacity, with net tension failure at W/D = 1.5 and bearing failure at W/D >= 2, irrespective of temperature. The W/D ratio exerted major influence on the bearing strength, maximum bearing strength was lower at low temperatures (LT; -60 degrees C) (390 MPa) and high temperatures (HT; 200 degrees C) (385 MPa) than that at room temperature (RT; 25 degrees C) (428 MPa). In comparison to RT, a reduction in specimen thickness at bearing area and accelerated localized kink collapse in 0 degrees lamina was observed for LT. The increased ductility of matrix at HT, resulting in fewer matrix cracks. These findings indicate the outstanding bearing load resistance of CF/PEKK composites, supporting their suitability for utilization in high-performance structures.

Automated summary

This study investigated the bearing strengths and failure behaviors of CF/PEKK composites at different temperatures, with varying W/D and E/D ratios. It was found that increasing the W/D ratio substantially amplified the pin load capacity, and the W/D ratio exerted major influence on the bearing strength. The CF/PEKK composites showed outstanding bearing load resistance, supporting their suitability for utilization in high-performance structures.