Optimization of a Composite Rotor Blade using a Genetic Algorithm with Local Search

Abstract

The material and ply angles of a fiber-reinforced plastic (FRP) rotor blade of a helicopter are optimized using a genetic algorithm (GA) with local search. The variation of the structural stiffness with material and ply angle is investigated. The aim of the optimization is to find an optimal stacking sequence that minimizes twist deformation. An optimum rotor blade is obtained using the ply angles as variables; failure, natural frequency, and minimum moment of inertia are used to constrain the optimization. The GA is employed as an optimization tool. A simplified local search is implemented in the final stage of optimization to reduce the searching time.

Isogeometric analysis and Genetic Algorithm for shape-adaptive composite marine propellers

“…The GA was considered because many of the classical gradient-based methods encounter difficulties when handling complex problems such as optimising composite layups and several other researchers have used GA based optimisation strategies in schemes for composite layups [4,13,16,31,32]. GAs are capable of handling both continuous variable and integer variable optimisation problems.…”

Smoothed finite element and genetic algorithm based optimization for shape adaptive composite marine propellers

“…Thus, the Genetic Algorithm (GA) was chosen as it can satisfy all these requirements. The GA has been used by several authors [30,27,8,9,31] in composite ply optimization tasks proving its attractiveness and credibility. The process of GA involves applying mutations to the ply angle configuration and evaluating whether the blade can achieve the required angle at the tip.…”

“…Both the GA and the FE solver were coded in the commercial numerical processing software Matlab™. Although it is possible to couple the GA with an existing commercial FEM solver as attempted by several authors in similar research [1,27,5,6,9], a coupled fully in-house solver is seen as a future proof approach. This is due to the inherent freedom the user has within such a solver and capability of improvement and further streamlining in the future.…”

“…The key requirement for the optimization technique proposed here is to achieve an efficiency curve for the composite propeller that is tangential to all the efficiency curves in the vicinity of the design (cruise) advance ratio of the vessel. In contrast to the approaches taken by previous researchers [27,9,3], the proposed method attempts to achieve accurate pitch angles derived from propeller efficiency curves based on many off-design points. It also gives the freedom to specify weightages to off-design points based on probabilities the blade is likely to operate at each off-design point.…”

Optimum Design of Composite Structures: A Literature Survey (1969–2009)

“…While maximizing stiffness, buckling strength, damping, natural frequency, etc. by modifying fiber orientations, material or thickness distribution, a static failure theory may be used 2,5,44,75,160,176,198,219,226,228,244,247,255,266,291,321,339,353,386,439,508,580,581,621,631,719,822,831,937,951,960,961 to guard against static failure. During weight minimization of pressure vessels, a lower limit may be imposed on the burst pressure.…”