Natural Vibration and Flutter of Elastically Supported Corrugation-stiffened Panels


Book Description

The natural vibration and flutter characteristics of two corrugation-stiffened panels were studied experimentally and theoretically to determine the effects of finite deflectional, rotational, and torsional stiffnesses of the boundary supports. Flutter tests were conducted at a Mach number of 3. The experimental data are compared with results from a flutter theory for orthotropic panels which includes the effects of finite support stiffnesses as well as uniform in-plane loading of the panel. The investigation indicates that finite deflectional, rotational, and torsional stiffnesses of the boundary supports must be accounted for in the theory in order to match experimental natural frequencies of the test panels. However, it is concluded that structural damping (neglected in the theory) strongly influenced the flutter behavior of the test panels. Furthermore, the theory shows that the addition of torsional stiffening at the supports is a definite asset for increasing flutter dynamic pressure and may be extremely important in the design of panels for application at hypersonic speeds where thermal expansion may be desired.




NASA Technical Note


Book Description







Natural Vibration and Flutter of Elastically Supported Corrugation-stiffened Panels


Book Description

The natural vibration and flutter characteristics of two corrugation-stiffened panels were studied experimentally and theoretically to determine the effects of finite deflectional, rotational, and torsional stiffnesses of the boundary supports. Flutter tests were conducted at a Mach number of 3. The experimental data are compared with results from a flutter theory for orthotropic panels which includes the effects of finite support stiffnesses as well as uniform in-plane loading of the panel. The investigation indicates that finite deflectional, rotational, and torsional stiffnesses of the boundary supports must be accounted for in the theory in order to match experimental natural frequencies of the test panels. However, it is concluded that structural damping (neglected in the theory) strongly influenced the flutter behavior of the test panels. Furthermore, the theory shows that the addition of torsional stiffening at the supports is a definite asset for increasing flutter dynamic pressure and may be extremely important in the design of panels for application at hypersonic speeds where thermal expansion may be desired.







Simulation Study of Three Instrument Displays to Assist in Airplane Thrust Management


Book Description

Three displays were evaluated on a piloted simulator, each of which provided information which could be used in thrust management. The three displays were (1) rate of change of speed, (2) potential flight-path angle, and (3) potential rate of climb. Results are presented in the form of time histories, histograms, and pilot comments. The results include comparisons of flight-path and speed control and throttle activity with and without each display and pilot comments.