Strain Gage Calibration Using Response to Dynamic Input (STURDI)

Impact Technologies, with support from the prime JSF manufacturer, Lockheed Martin Aeronautics Company, proposes to develop and demonstrate a system for in-situ calibration of strain sensors on in-service fleet aircraft that are used for structural life tracking. Key tasks in Phase I include: 1) Full definition of the performance specifications and constraints (e.g. safety) that the calibration technology must meet; 2) Selection of potential dynamic input technologies to test - this will include response to low levels of localized periodic forcing functions and controlled impact events; 3) Design and manufacture of test fixtures that adequately reproduce key aircraft structures found where strain gages would be placed in the target aircraft; 4) Creation of an analytical model of the structure to understand the fundamental physics involved and estimate the system’s sensitivity to changes in various input parameters; 5) Testing of the various dynamic calibration technologies by comparing the dynamic response features to response to static loads (i.e. the known baseline); 6) Demonstration of the ability of the techniques and calculation of accuracy in ‘blind’ tests for the Navy; and 7) Analyzing the potential of the technology to meet Navy goals in Phase II and beyond.