Accession Number : ADA192376

Title :   Structural Dynamics of Maneuvering Aircraft.

Descriptive Note : Final rept. Jul 86-Sep 87,

Corporate Author : CONRAD TECHNOLOGIES INC KING OF PRUSSIA PA

Personal Author(s) : Reddi, M M

PDF Url : ADA192376

Report Date : Sep 1987

Pagination or Media Count : 90

Abstract : The technical objectives of the research are to establish the minimum level of modeling necessary for predicting the dynamic stresses in fighter aircraft during maneuvers and transitions between maneuvers, to identify the physical phenomena which are significant, to identify potential shortfalls in current aircraft design technology and to identify areas for further research. A symmetric wing, modeled as a beam with quasi-steady aerodynamic loads introduced through the vortex lattice method, is used for the dynamic evaluation. The dynamical equations of motion are solved in the time domain by the Runge-Kutta method specialized to second order equations. The maneuver dynamic analysis program, MANDYN, written in Fortran 77, uses the parameters of real variable-geometry airplane. An extensive investigation of dynamic loads resulting from a simple maneuver for various severity levels revealed that the lowest natural frequency and load application time are significant factors in determining the validity of the load factor approach. Recommendations based on the study results are made. Keywords: Symmetrical maneuvers.

Descriptors :   *AERODYNAMIC LOADING, *MATHEMATICAL MODELS, *FLIGHT LOADS, *JET FIGHTERS, DYNAMIC LOADS, DYNAMICS, EQUATIONS, EQUATIONS OF MOTION, FLIGHT MANEUVERS, GEOMETRY, LOADS(FORCES), MANEUVERS, PHYSICAL PROPERTIES, RESONANT FREQUENCY, RUNGE KUTTA METHOD, STRESSES, STRUCTURAL RESPONSE, SYMMETRY, TEST AND EVALUATION, TIME, TIME DOMAIN, VARIATIONS, VORTICES, WINGS, AERONAUTICAL ENGINEERING, FORTRAN, NAVAL AIRCRAFT, STRESS ANALYSIS, TRANSITIONS, DYNAMIC RESPONSE, COMPUTER PROGRAMS

Subject Categories : Mechanics
      Military Aircraft Operations
      Attack and Fighter Aircraft

Distribution Statement : APPROVED FOR PUBLIC RELEASE