Woodruff School of Mechanical Engineering

Mechanical Engineering Seminar


Evolution of Structural Health Monitoring Solutions Through the Application of Embedded Sensor Networks


Dr. Dennis Roach


Sandia National Laboratories


Thursday, February 16, 2012 at 2:00:00 PM


MRDC Building, Room 4211


Bill Wepfer


Multi-site fatigue damage, hidden cracks in hard-to-reach locations, disbonded joints, erosion, impact, and corrosion are among the major flaws encountered in today’s extensive array of aerospace vehicles and civil structures. These damage scenarios, coupled with new and unexpected phenomena, have placed greater demands on the application of advanced nondestructive inspection (NDI) and health monitoring techniques. The use of in-situ sensors for real-time health monitoring of aircraft structures can be a viable option to overcome inspection impediments stemming from accessibility limitations, complex geometries, and the location and depth of hidden damage. Reliable, structural health monitoring (SHM) systems can automatically process data, assess structural condition, and signal the need for human intervention. Prevention of unexpected flaw growth and structural failure could be improved if on-board health monitoring systems are used to continuously assess structural integrity. Condition-based maintenance practices could be substituted for the current time-based maintenance approach. Other advantages of on-board, distributed sensor systems are that they can eliminate costly, and potentially damaging, disassembly, improve sensitivity by producing optimum placement of sensors with minimized human factors concerns in deployment, and decrease maintenance costs by eliminating more time-consuming manual inspections. The FAA Airworthiness Assurance Center at Sandia National Labs has been addressing these issues via a host of programs conducted jointly with the aviation industry. This seminar describes advanced NDI and SHM methods that are being evolved to detect structural damage and estimate residual life in commercial aircraft. It also addresses developments in mountable sensors and how these sensors can be integrated into SHM systems to accommodate condition-based maintenance approaches.


Dennis Roach is a Senior Technical Fellow in the Transportation Safeguards and Surety Organization at Sandia National Labs. Most of his work has been in the area of experimental and analytical assessment and nondestructive inspection of structures. Dr. Roach is the Chief Engineer in the FAA's Airworthiness Assurance Center and has worked in this Center since its inception at Sandia in 1991. His specialty is in damage tolerance and inspection of composite and metallic materials for civil and aerospace applications including the development of sensors for in-situ health monitoring. Before joining Sandia, he worked on the Space Shuttle program at Boeing and was a research fellow at the National Aerospace Laboratory in the Netherlands. He is a founding member of the Aerospace Industry Steering Committee on Structural Health Monitoring and chairs the International Commercial Aircraft Composite Repair Committee. He has over 150 technical publications including a co-authored book on the application of advanced composite materials and a co-authored book on in-situ Structural Health Monitoring. Dr. Roach received his degrees in Aerospace Engineering from the Georgia Institute of Technology and the University of Texas.