Self-sensing and self-healing of structural damage in fiber reinforced composites

Carbon fiber reinforced composites have been used in a wide range of applications in aerospace, mechanical, and civil structures. Due to the nature of material, multiple types of structural damage including micro matrix cracks and delaminations can significant degrade the integrity and safety of composites. It is difficult to detect and repair such damage since they are always barely visible to the naked eye. This paper presents the development of self-sensing and self-healing functions in order to detect damage progression and conduct in-situ damage repair in composite structures. Carbon nanotubes, which are highly conductive materials, are uniformly distributed within epoxy to develop the self-sensing capability. Shape memory polymer is used in the hot spot to obtain the self-healing capability. The developed multi-functional material is applied to carbon fiber reinforced composites for the autonomic detection and heal the matrix cracking. Experimental results showed that the developed composite materials are capable of detecting and healing the matrix cracks and delaminations. The developed self-healing material has the potential to be used as a novel structural material in mechanical, civil, aerospace applications. It can be used to detect and in-situ repair matrix damage induced by low velocity impacts and fatigues.