Experimental Investigation on the Effect of Multi‐Wrinkle Fiber Defects on the Compressive Testing of Unidirectional Composites

ABSTRACT Wrinkle defects have a significant effect on the mechanical characteristics of composites. Therefore, understanding the impact of these defects is crucial for the prudent usage of composite materials. Both unidirectional (UD) composites with single wrinkles of varied sizes embedded at various locations and multi‐wrinkle composites with different numbers of wrinkles at multiple positions were created in this study. The digital image correlation (DIC) measurement method was used to examine the material's compressive testing. The impacts of wrinkle location, size, and quantity on the materials' failure processes and compressive testing are methodically compared and summarized in this work. Delamination is identified as the primary failure mode, and the wrinkle region of the wrinkled specimens consistently experiences the highest strain. In contrast to their relatively small impact on compressive modulus, wrinkle amplitude, amount, and placement considerably affect compressive strength and failure mechanism.