APPLICATION OF GENERALIZED FORCE DETERMINATION TO A FULL SCALE LOW CYCLE FATIGUE TEST OF THE SH-2G HELICOPTER

As part of an overall Structural Life Assessment Program, a full scale low cycle fatigue test is currently being performed on a representative SH-2G airframe. This test is designed to reproduce the loads and mass/inertial responses that are imposed on the fuselage from various flight and landing conditions which the aircraft experiences throughout its service life. The test is performed for a period of 2 lifetimes using a flight spectrum representative of the fleet of SH-2 helicopters. Presented here is the methodology which was developed for conducting this type of full scale ground flying test. A process referred to as Generalized Force Determination (GFD) is used to quickly and reliably design the test set-up and load magnitudes which most closely represent the desired flight conditions. Measured flight test data of strains, internal loads, and accelerations along with pre-test calibration measurements are used by GFD to develop ground test requirements. In addition, GFD is shown to provide a means of improving the test configuration within the constraints of the user's available hardware.