The Boeing Company
System for temperature insensitive damage detection

Abstract:

A system for detecting damage in an aircraft structure includes an aircraft structure and a structural health monitoring (SHM) system for monitoring the health of the aircraft structure independent of temperature. The SHM system includes an actuator bonded to the aircraft structure and configured to generate a reference vibration signal having a reference amplitude that propagates through the aircraft structure at a first time, and generate a comparison vibration signal having a comparison amplitude that propagates through the aircraft structure at a second time after the first time. The comparison amplitude represents damage incurred by the aircraft structure between the first time and the second time. The SHM system includes a sensor bonded to the aircraft structure that receives the reference vibration signal and the comparison vibration signal, and a processor configured to compute a gain damage index as a function of the reference amplitude divided by the comparison amplitude.