Fleet Aircraft Strain Sensor Calibration System

To address the Navy need for a simple method to calibrate strain sensors on in-service aircraft with the accuracy of a full-scale test rig, Physical Optics Corporation (POC) proposes to develop a new Fleet Aircraft Strain Sensor Calibration system (FASCAL), based on the simultaneous measurement of aircraft frame deflections at several locations under a static loading condition. True strain/load on the aircraft¡¦s body frame is estimated from the measured deflection and a high-fidelity structural model, and it is compared with the strain sensor readings for accurate sensor calibration. Optical deflection sensors measure linear and angular deflections of the wings, vertical tail, horizontal stabilizer, and nose of the aircraft with +/-100 microns and +/-0.1 degree resolutions. The proposed strain sensor calibration system is configurable to any type of fleet aircraft and will require no time-intensive preparation steps or data acquisition. In Phase I, POC will demonstrate the feasibility of FASCAL by measuring structural deflections of a model of an aircraft when subjected to static loading and estimating the strain on the frames. In Phase II, POC plans to develop a full-scale FASCAL system, including signal processing and control electronics, which can be readily integrated into the Navy¡¦s aircraft maintenance facilities.