Layout Optimization for Blended Wing Body Aircraft Structure

Wensheng Zhu,Yu Wang,Xiongqing Yu

doi:10.1007/s42405-019-00172-7

Abstract

Structural layout design of blended wing body (BWB) aircraft in the preliminary design phase is a challenging optimization problem due to large numbers of design variables and various constraints. A two-loop optimization strategyis proposed to solve the BWB aircraft structural layout design problem considering constraints of the displacement, stress, strain, and buckling. The two-loop optimization consists of an inner loop and an outer loop. The inner loop is to optimize each stiffened panel of the BWB aircraft structure, and outer loop is to find the best layout design. To improve computational efficiency, an equivalent finite element model is applied to BWB aircraft structure analysis, and an analytical method is used for buckling and static analysis of the stiffened panels. The proposed method can efficiently solve the structural layout optimization problem of a notional BWB aircraft with acceptable computational burden. The result indicates the mass of main load-carrying structure of the BWB aircraft is reduced by 9.28% compared to that of the initial structural layout.

Highlights

Over the past decades, there has been great interest in improving the performance of transport aircraft for the reductions in fuel burn, noise and NOx emissions [1]
We propose a more straightforward strategy for layout optimization of blended wing body (BWB) aircraft structure
Structural stiffness reaches higher levels under more strict strength constraint, the increment of the stiffness can be achieved by updating the static strength failure factor by the violated percentage [26], which would be employed as new constraint criteria in the inner loop

Summary

Introduction

There has been great interest in improving the performance of transport aircraft for the reductions in fuel burn, noise and NOx emissions [1]. Nonconventional aircraft concepts, such as the BWB (blended wing body) aircraft, have been proposed for revolutionary improvement for future air transportation while the current generation civil transports cannot fulfill those requirements [2]. The BWB aircraft is a tailless design concept that integrates wing and fuselage. Since BWB is an unconventional configuration concept, there is a lack of experience and empirical data in the structural design of BWB aircraft. Several studies on structural design optimization of BWB aircraft have been conducted.

Methods

Results

Conclusion