This book presents the proceedings of the American Society for Composites 39th Technical Conference. This volume, the fourth of six volumes, provides a comprehensive overview of cutting-edge innovations and critical testing in composite materials, emphasizing their role in next-generation aeronautical and space applications. In-depth chapters cover repair methods, such as surface analysis to improve bonding, single vacuum bag processes for on-aircraft repairs, and epoxy vitrimers to extend service life and reduce waste. For composites in extreme environments, durability is explored through studies on epoxy coatings for electrified roadways, oxidation models for ceramics, and fire degradation simulations. Impact and dynamic response sections focus on data-driven low-velocity impact assessments, impact toughness, ballistic damage monitoring, origami-inspired structures, and high-energy impact modeling. Multifunctional composites are highlighted for their role in 3D-printed structural batteries, self-powered sensors for damage detection, and materials with enhanced mechanical and electrical properties for energy storage. Process modeling and optimization are also featured, with advancements in viscoelastic modeling, textile reinforcement mechanics, and induction bonding. This collection captures pioneering research and sets a foundation for future industry innovations.

This volume carries unique scholarly and engineering values due to the inclusion of advanced composite repair, multifunctionality, and process optimization alongside a wide range of multidisciplinary testing and evaluation techniques critical for certifying next-generation composites in industries like aerospace.