Session: 12-16-01: Multiscale Models and Experimental Techniques for Composite Materials and Structures Count

Paper Number: 114936

114936 - Investigating the Interlaminar Shear Strength of Short Carbon Fiber-Reinforced PEEK Composites Fabricated by Fused Filament Fabrication 

Carbon fiber (CF)-reinforced polyetheretherketone (PEEK) composites are highly valued for their exceptional physical and mechanical properties, such as high strength, stiffness, temperature resistance, chemical resistance, lightweight, and biocompatibility. These properties make them suitable for various industrial applications, including aerospace, automotive, medical, and electronics. However, the CF reinforcement in PEEK composites can lead to interlaminar weakening, reducing the interlaminar shear strength (ILSS) of the composite. Therefore, it is essential to investigate the ILSS of CF-reinforced PEEK composites to optimize their properties for different applications. In this study, short beam shear (SBS) tests were performed to quantify the ILSS of short CF-reinforced PEEK composites fabricated by the fused filament fabrication (FFF) technique. Unreinforced PEEK was used as the baseline for comparison. During the SBS tests, the digital image correlation (DIC) technique was used to measure in-situ full-field strain maps, enabling the observation of interlaminar failure mechanisms. The role of CF reinforcement and infill line orientation between adjacent layers on the ILSS of the PEEK composites was analyzed. The experimental findings show that the CF reinforcement reduces the average ILSS of the PEEK composites by about 20%. This reduction is attributed to interlaminar weakening resulting from the CF reinforcement. Additionally, the ILSS strongly depends on the infill line orientation between adjacent layers. There is a positive correlation between the ILSS and the relative angle between the adjacent layers. When the infill line orientation is parallel to the direction of the shear load, the ILSS is the lowest. On the other hand, when the infill line orientation is perpendicular to the direction of the shear load, the ILSS is the highest. The results presented in this study have significant importance for the design and manufacturing of stronger and tougher CF-reinforced PEEK composites. The findings suggest that the infill line orientation and CF reinforcement should be carefully considered to optimize the ILSS of the PEEK composites for various industrial applications. The proper selection of the infill line orientations can result in up to 40% improvement in the ILSS of the short CF-reinforced PEEK Composites. The DIC technique used in this study provides a useful tool to investigate interlaminar failure mechanisms and to optimize the design and manufacturing of CF-reinforced PEEK composites. Further studies could explore the effect of other variables, such as the CF content, on the ILSS and mechanical properties of the PEEK composites. The findings suggest that the infill line orientation and CF reinforcement should be carefully considered to optimize the ILSS of the PEEK composites for various industrial applications, such as aerospace, automotive, medical, and electronics.

Presenting Author: Denizhan Yavas Lamar University

Presenting Author Biography: Denizhan Yavas is an assistant professor in the Department of Mechanical Engineering at Lamar University, Beaumont, Texas. He holds a doctoral degree in aerospace engineering (major in engineering mechanics) from Iowa State University, M.Sc. and B.S. degrees in aerospace engineering from Middle East Technical University in Turkey.

Authors:

Denizhan Yavas Lamar University
Luis Sosa Lamar University