Optimal design of fighter aircraft wing panels laminates under multi-load case environment by ply-drop and ply-migrations. (1st January 2019)

• Record Type: Journal Article
• Authors: Shrivastava, Sachin; Mohite, P.M.; Limaye, M.D.
• Is Part Of: Composite structures. Volume 207(2019)
• Page Start: 909
• Page End: 922
• Publication Date: 2019-01-01
• Subjects: Ply-drop -- Ply migration -- Composite wing box design -- Laminate blending -- Multi-objective optimization -- Python-scripting; Composite construction -- Periodicals; Composites -- Périodiques; 624.18
• DOI: 10.1016/j.compstruct.2018.09.004
• Languages: English
• ISSNs: 0263-8223

Abstract

Abstract: The ply-drop (PD) is termination of specific plies at rib-axis for getting tapered laminates. The present optimization study aims to achieve minimum weight tapered wing panels laminates by PD followed by ply-migrations (PM). The PM are required for ply-continuity (blending) and achieving smooth external aerodynamic surface. A genetic-algorithm mutation operator and fitness based search algorithm is developed in the present study for the optimization. The laminate weight minimization has been achieved as goal of multi-objective optimization (MOO), by utilizing excess design margins of Tsai-Wu first ply failure-index (FI) and wing tip lateral deflection. The finite-element (FE) model of laminate is a set of discrete laminates (chromosomes) between ribs with continuity by virtue of ply-orientations. To select best fit laminate, ply orientations were randomly selected and perturbed for thickness during optimization. The fitness function for evaluating chromosomes is a composite function of multi-objective design requirements and design constraints. The algorithm submits orientation/thickness combinations to ABAQUS/CAE by python-script for function evaluation. The application of algorithm over an initially assumed quasi-isotropic laminate of uniform thickness showed 57% weight reduction for a fighter aircraft's wing panel. The optimization process is automated making PD practically viable in the design process itself.