NASA Logo

NTRS

NTRS - NASA Technical Reports Server

Back to Results
Computation of maximum gust loads in nonlinear aircraft using a new method based on the matched filter approach and numerical optimizationTime-correlated gust loads are time histories of two or more load quantities due to the same disturbance time history. Time correlation provides knowledge of the value (magnitude and sign) of one load when another is maximum. At least two analysis methods have been identified that are capable of computing maximized time-correlated gust loads for linear aircraft. Both methods solve for the unit-energy gust profile (gust velocity as a function of time) that produces the maximum load at a given location on a linear airplane. Time-correlated gust loads are obtained by re-applying this gust profile to the airplane and computing multiple simultaneous load responses. Such time histories are physically realizable and may be applied to aircraft structures. Within the past several years there has been much interest in obtaining a practical analysis method which is capable of solving the analogous problem for nonlinear aircraft. Such an analysis method has been the focus of an international committee of gust loads specialists formed by the U.S. Federal Aviation Administration and was the topic of a panel discussion at the Gust and Buffet Loads session at the 1989 SDM Conference in Mobile, Alabama. The kinds of nonlinearities common on modern transport aircraft are indicated. The Statical Discrete Gust method is capable of being, but so far has not been, applied to nonlinear aircraft. To make the method practical for nonlinear applications, a search procedure is essential. Another method is based on Matched Filter Theory and, in its current form, is applicable to linear systems only. The purpose here is to present the status of an attempt to extend the matched filter approach to nonlinear systems. The extension uses Matched Filter Theory as a starting point and then employs a constrained optimization algorithm to attack the nonlinear problem.
Document ID
19910001004
Acquisition Source
Legacy CDMS
Document Type
Conference Paper
Authors
Pototzky, Anthony S.
(Lockheed Engineering and Sciences Co. Hampton, VA., United States)
Heeg, Jennifer
(NASA Langley Research Center Hampton, VA, United States)
Perry, Boyd, III
(NASA Langley Research Center Hampton, VA, United States)
Date Acquired
September 6, 2013
Publication Date
March 1, 1990
Publication Information
Publication: Research in Structures, Structural Dynamics and Materials, 1990
Subject Category
Structural Mechanics
Accession Number
91N10317
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.
No Preview Available