Weight optimization of a composite wing-panel with flutter stability constraints by ply-drop
- PDF / 4,726,369 Bytes
- 15 Pages / 595.224 x 790.955 pts Page_size
- 103 Downloads / 197 Views
INDUSTRIAL APPLICATION PAPER
Weight optimization of a composite wing-panel with flutter stability constraints by ply-drop Sachin Shrivastava1 · Hitesh Tilala2 · P. M. Mohite1 · M. D. Limaye3 Received: 18 August 2019 / Revised: 8 February 2020 / Accepted: 3 March 2020 © Springer-Verlag GmbH Germany, part of Springer Nature 2020
Abstract The existing approach in aircraft wing design optimizes the structure for strength and buckling design criteria followed by a flutter stability check, which leads to design that may not be optimal. This study proposes the flutter stability as an integral of weight optimization by a two-step procedure. Step 1 comprises series of flutter and static analyses of finite element (FE) models with different weapon configurations and aerodynamic loads, which give limiting values of wing tip deflection and wing twist as flutter constraints. Step 2 focuses on weight optimization of the laminate for strength and stiffness design parameters along with the flutter constraints. The algorithm minimizes structural weight by ply drop, which is based on evaluation of the fitness value of laminates generated by a stochastic operator. The ply drop design algorithm is applied to optimize the FE model of a fourth-generation fighter aircraft wing box with three representative aerodynamic loads and three weapon configurations. The application evolved optimal laminate with seamless and symmetric plies, which has 35% lesser weight compared with the initial model having quasi-isotropic laminates for given strength and flutter stability design requirement. The application of genetic algorithm (GA) to get an initial laminate instead of quasi-isotropic laminates further improved the design by 2.5% weight reduction. Keywords Ply drop · Ply migration · Flutter constraints · Wing box design optimization · Automated ply deletion · Genetic algorithm
1 Introduction Wing design is based on strength, buckling, and flutter stability, in which strength and buckling correspond to structural integrity design requirements. However, flutter stability is a dynamic aero-elastic design requirement, which calls for critical flutter velocity of structure should be at least 15% higher than the operating speed in the entire flight regime as per MIL 8870C. Flutter is an undesirable phenomenon in aircraft as it causes divergent oscillations that may lead to structural damage or failure, performance and ride comfort Responsible Editor: Yoojeong Noh P. M. Mohite
[email protected] 1
Department of Aerospace Engineering, Indian Institute of Technology Kanpur, Kanpur, UP, 208016, India
2
AURDC, Hindustan Aeronautics Limited, Nasik, MH, 422207, India
3
R&D Engineers, DRDO, Pune, MH, 411015, India
degradation, or loss of control. If flutter gets discovered at the aircraft certification stage, a costly redesign is required. The mitigation of flutter is possible by proper governing of the flutter parameters at the design stage itself. The flutter velocity of a wing structure is a function of aerodynamic load, structural stiffness, and
Data Loading...
