Multifunctional Fibers for Damage Detection in Reinforced Composites

Regents Of The University Of Michigan - Ann Arbor, Ann Arbor MI

Investigators

Abstract

Fiber reinforced polymer composites are revolutionizing the future of structural materials by providing more materials that are lighter and more energy efficient. Such composite materials, however, are susceptible to a number of failure modes and it is difficult to identify the reasons behind the failures using the traditional nondestructive evaluation techniques that exist today. This research seeks to develop a new approach to monitor the integrity of composite materials using piezoelectric sensors that can convert deformations of material into electrical signals. By interpreting these signals, it may be possible to determine a material's operational lifetime. If successful, this advance will lead to a paradigm shift in use of fiber reinforced polymer composites through the integration of damage detection sensors into the materials such that they simultaneously enhance mechanical strength. Broader impacts of this project extend from advances in nondestructive evaluation and structural health monitoring, to smart materials. The proposed education and outreach program is also comprehensive. This effort focuses on the development of true multifunctional fiber reinforced composites that can use functional materials to both enhance strength and provide embedded damage sensing. The main objective of this research is to advance the current state of art in the fabrication of the next generation of structural composites and structural health monitoring methods. The research will perform a fundamental investigation into the development of embedded and distributed SHM sensors in fiber reinforced composites based on a piezoelectric whiskerization technique recently developed by the PI. The approach will seek to utilize the piezoelectric interphase as a pseudo acoustic emission system where rather than tracking the released of elastic energy as an acoustic wave, the composite will produce a voltage output. Our research will seek to elucidate the behavior of these unique interfaces in the presence of damage and to develop experimental methodologies to probe the mechanical integrity of the material. The development of the proposed damage detection schemes for composite materials would provide a critical tool to advance safety in this growing class of materials. Furthermore, these processes can reduce maintenance costs by forgoing schedule based maintenance for data based repairs. Beyond the economic impacts of this work, interfaces are ubiquitous and the tools developed will provide a modern materials research approach for electronics, catalysis and other applications where bonding between dissimilar materials is relevant. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.