Topology optimization and experimental validation of mass-reduced aircraft wing designs

Abstract

Development and evaluation of a novel design of mass reduced aircraft wing ribs through topology optimization is reported herein. For comparison, the same examination is performed on ribs with normal internal geometry. The wing rib design is based on the Gulfstream G650 transonic jet. The rib is divided into three segments for analysis based around the positions of the two spars. Only the center section of the rib is mass optimized, while the leading and trailing edges of the ribs are kept solid. Methodology in this study includes the k-Ω shear stress transport turbulence model computational fluid dynamic simulation as well as static and transient finite element simulations. The optimized wing rib is found to be between 8% and 15% lighter than traditional wing ribs depending on configuration. Simulation of the wing showed a tip deflection of 13.8 cm upward at an angle of 1.1°. An experimental scaled model of the optimized wing subjected to near identical bending loads as identified in the FEA simulation is applied to validate stress concentrations and performance. It is found that in the simulations, average stress never exceeded the factor of safety prescribed by the FAA. While the average factor of safety on the full computational model was 2.649, the average factor of safety on the experimental model was 9.185. Four strain gauges attached to the experimental model are used to compare the strains at similar locations on the computational model. The experimental results validate the CFD simulation results with acceptable tolerances.