Reliability-based aeroelastic optimization of a composite aircraft wing via fluid-structure interaction of high fidelity solvers Abstract. We consider reliability based aeroelastic optimization of a AGARD 445.6 composite aircraft wing with stochastic parameters. Both commercial engineering software and an inhouse reliability analysis code are employed in this high-fidelity computational framework. Finite volume based flow solver Fluent is used to solve 3D Euler equations, while Gambit is the fluid domain mesh generator and Catia-V5-R16 is used as a parametric 3D solid modeler. Abaqus, a structural finite element solver, is used to compute the structural response of the aeroelastic system. Mesh based parallel code coupling interface MPCCI-3.0.6 is used to exchange the pressure and displacement information between Fluent and Abaqus to perform a loosely coupled fluid-structure interaction by employing a staggered algorithm. To compute the probability of failure for the probabilistic constraints, one of the well known MPP (Most Probable Point) based reliability analysis methods, FORM (First Order Reliability Method) is implemented in Matlab. This in-house developed Matlab code is embedded in the multidisciplinary optimization workflow which is driven by Modefrontier. Modefrontier 4.1, is used for its gradient based optimization algorithm called NBI-NLPQLP which is based on sequential quadratic programming method. A pareto optimal solution for the stochastic aeroelastic optimization is obtained for a specified reliability index and results are compared with the results of deterministic aeroelastic optimization.
IntroductionThe challenging task of aircraft design requires a systematic approach which can couple several engineering disciplines in the design process. Today, this task can be more efficiently and accurately performed by employing high fidelity tools in collaboration with multidisciplinary optimization techniques. The improvement of multidisciplinary optimal design depends on the fidelity level of the individual analysis used inside each discipline, how effectively the coupling method handles interaction between the disciplines and also the computational efficiency and accuracy of the algorithm used to solve the optimization problem. As being one of the most important criteria of aircraft design, aeroelasticity requires high fidelity level solutions for the fluid-structure interaction phenomena for real complex geometries. Besides, the reliability level of the proposed design is an important criteria in decision making for production of an aircraft. Thus, recently, reliability based aeroelastic optimization of aircraft structures has