Design Of Aerospace Structures Research Articles

A dual formulation for generating information about constrained optima in automated design

Certain properties of geometric programming are used to develop a method for generating information about the optimum design for problems involving the minimization of a real valued function subject to inequality constraints. This information includes a lower bound on the global minimum value of the merit function, details of which constraints are active at the optimum and values of the characteristics associated with non-active constraints. An active set strategy is then presented to obtain the optimum design without invoking a formal search procedure. Approximations will usually be required for the merit function and constraints, and accuracy and convergence are considered. Application of these methods to problems associated with the minimum weight design of aerospace structures is demonstrated.

Automated Design of Aerospace Structures

The current state-of-the-art in structural analysis of aerospace vehicles is characterized, automated design technology is discussed, and an indication is given of the future direction of research in analysis and automated design. Representative computer programs for analysis typical of those in routine use in vehicle design activities are described, and results are shown for some selected analysis problems. Recent and planned advances in analysis capability are indicated. Techniques used to automate the more routine aspects of structural design are discussed, and some recently developed automated design computer programs are described. Finally, discussion is presented of early accomplishments in interdisciplinary automated design systems, and some indication of the future thrust of research in this field is given.

Structural response to random acoustic excitation

AbstractThe design of aerospace structures necessitates the study of their behaviour in intense acoustic environments. This is more so in recent times due to an increase in power of the vehicles. The present paper deals with an investigation of the response of structures such as flat, stiffened plates to such environments. A peaked type of power spectral density of excitation is assumed, which is more realistic and representative of actual random acoustic excitations than the conventionally assumed white noise type excitations, either ideal or band‐limited. The space correlation of the excitation field is assumed to be unity over the plate surface. Generalized harmonic analysis is used to obtain responses such as auto‐correlation functions and mean square values of both accelerations and stresses. To obtain the response quantities of stiffened plates the approximate method of analysis suggested by Lin12 is used.