AH64D APACHE LONGBOW AIRFRAME DYNAMIC TESTING

An extensive suspended airframe shake test of the AH64D Apache Longbow has been conducted. Three mission configurations were tested so that the variations of the structural dynamic properties with configuration changes could be evaluated. Nonlinear behavior in the structure was investigated by measuring the response at different load levels. A simple but effective method for introducing moment input into the structure has been demonstrated. The use of random excitation was tested and its effectiveness is compared with the traditional stepped sine method. The data gathered in this survey are compared with the previous ground vibration survey results on the AH-64A configuration. Advancements in data acquisition equipment provided significantly higher quality data than that obtained in previous shake testing. The data were correlated with analyses using the existing NASTRAN model of the AH- 64D.