Probabilistic Optimum Design of Aircraft Structures

Abstract

This paper discusses the application of probabilistic design methodology for the optimum design of aircraft structures. Material properties and loads are considered as stochastic data in formulating the optimization model for the design. The procedure accommodates various types of sensitivity analyses. Attention is focused on studies in which both the aerodynamic and structural designs are optimized simultaneously. Tradeoffs between drag and structural weight for aircraft wings are affected by two aerodynamic-structural interactions. First, structural weight affects the required lift and, thus drag. Second, structural deformations change the aerodynamic shape. Design results obtained using the Monte Carlo simulation method, and the limit state function approach, are presented. The limit state function method applies the Most Probable Point (MPP) search approach. Some of the approximate methods that have been applied for the search are FORM, AMV, AIS, etc.