News Article

Fatigue Crack Detection
Date: Jan 01, 2012
Source: ARMY SBIR Success Story ( click here to go to the source)

Featured firm in this article: Acellent Technologies Inc of Sunnyvale, CA

Safety and dependability of vehicle and aircraft structures are of great concern to the Army and are paramount for force protection. Unfortunately, current inspection and maintenance procedures for in-service systems can be time consuming, costly, and are labor intensive. Acellent Technologies has developed an innovative sensor cluster-based structural health monitoring system that combines Acellent's current single element SMART Layer actuator/sensor network with multi-element phased arrays to produce a Sensor Cluster Network.

The system can quantitatively assess structural damage such as cracks due to fatigue, identify damage in inaccessible areas of structures, characterize damage growth and provide an image of the damage size and orientation. Acellent's SMART Layer technology uses a network of miniature piezoelectric elements to transmit and receive acousto-ultrasonic signals. Features from the acousto­ultrasonic signals are extracted and used to detect, locate and estimate the size of any existing cracks. This system provides an innovative alternative that can significantly reduce inspection costs, enhance the reliability of the structures and improve their efficiency and readiness.

Technology Transition:
Acellent Technologies has received $1.6M toward commercializing this effort. The system is being tested under several Cooperative Research and Development Agreements (CRADAs) with the Army Research Laboratory (ARL), through which the SMART Layers have been installed on the tailboom of a Black hawk and flying for over 2 years. Also, the system is being tested as part of the Operations Support and Sustainment Technologies (OSST) program with Bell helicopters targeted at U.S. Army helicopters. In the OSST program, Acellent's system was tested on a rotorcraft component and demonstrated the capability to detect, locate, and characterize damage (fatigue cracking, battle damage, etc.). The system is currently undergoing MIL-STD testing along with flight tests and integration with the Oh-58D health and UsageMonitoring system for implementation within a 2-year timeframe. The product is also being evaluated by the Federal Aviation Administration (FAA), Sikorsky for rotorcraft applications and Boeing, Airbus, Embraer, and Bombardier for commercial aircraft applications. This development is also supported by British Petroleum (BP) for fixed base structures.