Co-authors​ :

 Manatsawee LIMPRAPUWIWATTANA (AUSTRALIA), Anil R. RAVINDRAN , Everson KANDARE (AUSTRALIA), Pier MARZOCCA , Raj B. LADANI  

Carbon fibre-reinforced polymer (CFRP) composites are used in various industries, such as aerospace and automotive, due to its lightweight and robust characteristics such as high strength to weight ratio. However, fibre-reinforced polymer composites are susceptible to intralaminar and interlaminar delamination damage, caused by events such as low-velocity impact damage, cyclic loading, and/or excessive applied load. Numerous through-the-thickness reinforcement methods have been proposed to mitigate delamination issues in laminated composites. Examples of these reinforcement methods include z-pinning, stitching, anchoring, braiding, and tufting. Among these methods, tufting is a relatively new approach that has proven to enhance the fracture toughness properties of composite materials. Tufting is performed on dry composite fabric layers, where various types of reinforcement materials can be used, including carbon, aramid, glass, copper, steel, and shape memory alloy wires. More recently, there has been a significant emphasis on smart and multifunctional materials, where additional properties such as self-healing and damage detection in composite materials are desirable.

This research illustrates the utilisation of Nickel-Titanium (Ni-Ti) based Shape Memory Alloy (SMA) wire for enhancing the fracture toughness and fatigue properties of tufted composite materials. The study also highlights the multifunctional aspects of tufted composites, encompassing self-healing and damage detection. The Nickel-Titanium (Ni-Ti) based Shape Memory Alloy (SMA) wire was incorporated by tufting onto plain-woven carbon fibre preforms at an areal content of only 0.30%, prior to resin infusion. The SMA-tufted composites exhibited improvements to their fracture properties under both quasi-static and cyclic loading conditions due to the formation of a large scale crack bridging zone as shown in Figure 1. Furthermore, the shape memory effects of the Ni-Ti tufts promote the ability to close delaminations via thermal heating. Additionally, the SMA tuft was employed to showcase its ability to detect cracks through monitoring changes in electrical resistance during loading. This research illustrates the utilisation of Nickel-Titanium (Ni-Ti) based Shape Memory Alloy (SMA) wire for enhancing the fracture toughness and fatigue properties of tufted composite materials. The study also highlights the multifunctional aspects of tufted composites, encompassing self-healing and damage detection.