Development of an airframe intensity based structural health monitoring system

An overview of the ongoing development of an Airframe Structural Intensity (SI) based damage detection technique is presented in this paper. SI is a measure of the active vibrational energy flow through a structure and is a vector quantity characterized by both its magnitude and direction. Previous studies have identified potential damage detection sensitivity enhancements offered by SI over traditional vibration based metrics. In this work the application of an active SI approach to the problem of airframe damage detection and localization was explored and enhanced techniques developed. Key results include both linear and non-linear SI implementations. Instrumented test structures were designed and assembled for modeling and sensor/algorithm development and validation. The developed method's ability to detect structural damage was experimentally validated and its structural damage detection and localization capabilities quantified. The results show good damage detection sensitivity for the linear SI implementation using a baseline approach. The nonlinear SI results show significantly enhanced damage sensitivity and the added benefit of being a baseline free method. The resulting computational model based tools for SHM system development, and the sensors/signal processing algorithms can be applied to airframe and drive systems.