A Model-assisted Damage Diagnostics and Characterization(MoDDiaC) wireless-sensor network based Structural Health Monitoring System for Composite Rotorcraft Applications Navy SBIR FY2012.2 Sol No.: Navy SBIR FY2012.2 Topic No.: N122-110 Topic Title: A Model-assisted Damage Diagnostics and Characterization(MoDDiaC) wireless-sensor network based Structural Health Monitoring System for Composite Rotorcraft Applications Proposal No.: N122-110-0495 Firm: Acellent Technologies, Inc. 835 Stewart Drive Sunnyvale, California 94085-4514 Contact: Sang Lee Phone: (408) 745-1188 Web Site: www.acellent.com Abstract: Advanced composite materials, increasingly adopted for airframe structures, are susceptible to barely visible impact damage, which has the potential to lead to a catastrophic failure if not accurately monitored. Structural health monitoring (SHM) based on acousto-ultrasound method has emerged as a promising technique for monitoring the onset and progress of structural damage. Acousto-ultrasound based SHM system employs generation and propagation of stress waves through attached piezoelectric transducers giving necessary information for monitoring the health of the structure. However, these techniques are generally suitable for simple structures without any local property /thickness variations. In this SBIR program, Acellent proposes to develop an innovative model-assisted SHM system that is capable of detecting, locating and characterizing type of damage on composite rotocraft structures. The proposed system learns sensitive signal features through a physics based wave propagation simulations and utilizes the knowledge to optimize sensor network for the given structure, and integrates offline learning with the current sensor data to accurately locate the damage even for complex structure with local property/thickness variation. Prototypes of the proposed model-assisted SHM system will be developed and demonstrated under representative loading and environmental conditions. Functionality of the proposed system will be tested thouroughly for different damage types. Benefits: The largest and nearest-term impact areas for the technology are large composite structures and inaccessible areas in today's rotorcraft. Economic factors drive the need to keep rotorcraft in-service for longer periods of time, often well beyond their designed service life. As these structures age, there is an increasing need for inspection to ensure public safety, ensure combat readiness and schedule maintenance effectively. The high cost of owning and operating these systems provides incentives for enhancing the means of evaluating and monitoring their structural integrity. The big challenge to the rotorcraft industry is that it must maintain a high standard of safety with its fleet in an economic environment that is intensely competitive. The proposed system could potentially lead to significant savings related to the labor-intensive scheduled maintenance costs in the rotorcraft industry, can enhance the reliability of the structures and improve their efficiency and readiness. The proposed work will be conducted in close collaboration with Bell Helicopters to ensure that this work will be directly beneficial to them. Return