Optical Fiber-Coil Sensors for Structural Health Monitoring (Tracking ID 20-000001103)
Abstract
The goal of the research is to study a novel sensor platform based on fiber-optic coils for crack detection in solid structures. Wewill study two different configurations and sensing mechanisms. The first is acoustic emission (AE) sensor consisting of two weak fiber Bragg gratings (FBGs) fabricated at the ends of tightly coiled fibers. In the second configuration, the fiber coils surround and monitor critical areas of the structure by measuring the strain profile along the coil in a distributive way with high spatial resolution. We hypothesize that the plastic strain at the tip of the crack cause permanent perturbations to the strain profile around the coil. Non-plastic strains and thermal strains from an undamaged structure are not expected to lead to permanent changes to the strain profile. Therefore, monitoring the strain profile around the fiber coil has the potential to reliably detect the presence and the growth of the cracks inside the coil. If successful, this project will address the key technical challenges in the development of practical AE sensor systems with desirable or improved performances in terms of detection sensitivity, coverage range, reliability, and system cost. Such a system can provide health monitoring during the service and does not affect the operation of the platforms. In addition, the project will also yield a new method for reliably monitoring the cracks at various critical locations in the structure. The research will provide us with powerful tools that will enable us to detect structural flaws and defects in a large area before they become a safety concern, which will significantly improve Navys ability to conduct systems maintenance and repairs with increased safety confidence levels and at reduced costs.Approved for Public Release
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Apr 06, 2021
- Source ID
- N000142112273
Entities
People
- Ming Han
Organizations
- Michigan State University
- Office of Naval Research
- United States Navy