Challenges and Approach for SHM Technology Transition

A large number of aircraft currently in service have exceeded their design life. Many of these aircraft form the backbone of the operational fleet. Safety, reliability, and lifecycle costs are of great concern for these aging aircraft. Current inspection techniques require the aircraft to be removed from service and the structure to be disassembled, which is labor intensive and time consuming, and significantly adds to sustainment costs. Recent advances in sensor technology, material processing, damage modeling, and system integration have enabled new developments in inspection technologies and structural evaluation to overcome the shortcomings of existing inspection systems. Acellent Technologies is currently developing structural health monitoring systems utilizing permanently installed sensors to address these issues. This paper addresses the challenges involved in the development and transition of this technology including issues concerned with design, installation and validation methods for damage detection. Results of testing conducted with the system on simple and complex components will be discussed along with practical issues concerning the implementation and use of the system on aircraft structures. Particular focus will be on system development for detecting stress corrosion cracking on KC-135 structure and pitting corrosion detection in multi-layered structural components, such as the XW155.024 chord of the F-15.