Neubacher, MarcelMarcelNeubacherTouni, FaridaFaridaTouniFiedler, BodoBodoFiedler2026-01-312026-01-312025In: Advances on composite materials and solid mechanics - a tribute to Professor Federico París. - Universidad de Sevilla (2025)https://hdl.handle.net/11420/61205Thin-ply composites are known for their superior in-situ strength and manufacturing quality, offering higher unnotched tensile and compressive strengths compared to conventional laminates. However, their damage suppression capability leads to increased notch sensitivity, where delamination and matrix cracking mechanisms are suppressed. As a result, thin-ply laminates are limited in their use in critical load-bearing applications.To address this, bioinspired Bouligand structures, defined by their helical fiber arrangements, have shown promise in reducing notch sensitivity through helicoidal matrix cracking and stress redistribution. This study explores the mechanical performance of partial Bouligand layups derived from biological fiber architectures observed in coelacanth fish scales, where fibrils reorient under load [1]. An analytical stiffness based optimization was performed to match the mechanical properties of the conventional [0 °, ±45 °, 90 °] (50 %, 40 %, 10 %) load introduction layup used in bolted and riveted aircraft structures [2, 3], while integrating the partial Bouligand structure.Two layer fiber areal weights (30 gsm and 60 gsm) were investigated, resulting in different pitch and stack angles. Tensile and bearing tests were conducted to evaluate the influence of the partial Bouligand structure on notch sensitivity. The results indicate that nature inspired fiber orientation can improve load redistribution and damage tolerance in thin ply laminates, making them compatible for off-axis and notched applications.enhttp://rightsstatements.org/vocab/InC/1.0/Bio-InspiredBouligandCFRPNotch sensitivityCLTTechnology::620: Engineering::620.1: Engineering Mechanics and Materials ScienceTechnology::629: Other Branches::629.1: AviationNatural Sciences and Mathematics::570: Life Sciences, BiologyBook Parthttps://doi.org/10.15480/882.1660810.15480/882.16608Book Chapter