Nastran Modeling Of Flight Test Components For Uh 60a Airloads Program Test Configuration PDF Download

Preceding program flight tests, a ground vibration test and modal test analysis of a UH-60A Black Hawk helicopter was conducted by Sikorsky Aircraft to complement the UH-60A test plan and NASA/ARMY Modern Technology Rotor Airloads Program. The 'NASA/AEFA' shake test configuration was tested for modal frequencies and shapes and compared with its NASTRAN finite element model counterpart to give correlative results. Based upon previous findings, significant differences in modal data existed and were attributed to assumptions regarding the influence of secondary structure contributions in the preliminary NASTRAN modeling. An analysis of an updated finite element model including several secondary structural additions has confirmed that the inclusion of specific secondary components produces a significant effect on modal frequency and free-response shapes and improves correlations at lower frequencies with shake test data. Idosor, Florentino and Seible, Frieder Unspecified Center FINITE ELEMENT METHOD; GROUND TESTS; MATHEMATICAL MODELS; NASTRAN; STRUCTURAL ANALYSIS; UH-60A HELICOPTER; VIBRATION TESTS; AERODYNAMIC LOADS; AIRCRAFT STRUCTURES; ROTORS...