Through-thickness reinforcement for woven laminates
Fiber reinforced polymer composites have gained popularity in aerospace and naval applications due to their tailorable mechanical properties and high strength-to-weight. Despite these advantages, between the layers of fabric (laminas), there is a resin-rich region known as interlaminar region, with no reinforcement which is very susceptible to damage. Different types of reinforcements have been tested for the interlaminar region. However, all of these methods have proved to decrease the in-plane properties due to damage to the fibers. In this thesis, a new reinforcement technique with ZnO nanowires is proposed to increase the damage resistance. This thesis describes the design, manufacturing and testing of woven composites with ZnO nanowire reinforcement. Damage resistance and durability of these composites are evaluated under quasi-static loading (Mode-I and Mode-II) and under dynamic loading (impact). Nanowire reinforcements appear to increase the damage resistance of a composite without reducing the in-plane properties of the composite. For quasi-static loading, the improvement of the interlaminar fracture toughness for Mode-I and Mode-II was approximately 74% and 28%, respectively. For dynamic loading, the damage degree was reduced by approximately 18%. This improvement is attributed to the resistance of nanowire reinforcement towards creating new surfaces.
Castellanos, Alejandra G, "Through-thickness reinforcement for woven laminates" (2016). ETD Collection for University of Texas, El Paso. AAI10118238.