Multimodal Damage Detection in Self‐Sensing Fiber Reinforced Composites

Abstract

AbstractInternal delamination damage is detected in fiber reinforced polymer composite materials containing active functionality. Damage‐triggered magnetization of the delaminated zone is accomplished using a vascular system to deliver fluids that precipitate magnetic particles upon mixing. Multiple modes of detection are used to sense the presence of this magnetic material. Visual detection is accomplished by the high contrast between damaged and undamaged areas provided by the biomimetic “bruise” formed by the magnetic particles. Magnetic scanning is also used to detect the particles, even if obscured by paint or by opaque reinforcement, such as carbon fiber. Additionally, thermal detection is accomplished by inductively heating the magnetic particles and sensing the temperature differential with an infrared camera. The effectiveness of each detection mode is discussed and compared to industry standard C‐scan to assess accuracy. Using the damage area measured with C‐scan as the benchmark, visual detection measures the damage area with 76% accuracy, and magnetic detection measures the damage area with 91% accuracy. Thermal detection accuracy is time‐dependent as expected. All detection modes consistently detect the presence of damage. The multifunctionality of this material can tailor damage detection techniques for the application and provide a parallel system to augment and potentially enhance self‐healing.