Investigating the Impact of Bio-Inspired Structural Design on the Fatigue Life of Lightweight Metallic Alloys

Abstract

This study explores the influence of bio-inspired structural designs on the fatigue life of lightweight metallic alloys, specifically AA7075 aluminum and Ti-6Al-4V titanium. Using advanced additive manufacturing techniques, three bio-inspired geometries—honeycomb, trabecular, and cellular lattice—were fabricated and compared to traditional solid block designs under cyclic loading. The results revealed significant improvements in fatigue life for the bio-inspired designs, with the honeycomb structure showing up to a fourfold increase for AA7075 and a threefold increase for Ti-6Al-4V. Stress-life (S-N) curve analysis and Weibull distribution demonstrated the enhanced fatigue resistance and reliability of these designs, while fractographic examination confirmed their ability to distribute stress more effectively and delay crack initiation and propagation. The findings suggest that bio-inspired designs can substantially extend the lifespan and reliability of components in fatigue-prone applications, making them highly suitable for aerospace, automotive, and biomedical engineering. Moreover, this research highlights the potential of additive manufacturing to create complex, optimized geometries, offering new pathways for material efficiency and sustainability in modern engineering.