OPTIMIZATION OF AIRCRAFT WING STRUCTURE

Abstract

In this research, the optimum design of a manned aircraft wing structure at speed (M=0.4) is estimated for both isotropic and orthotropic material. Firstly the stress analysis for wing structure due to aerodynamic loads is computed. The wing is considered as a cantilever through the contact points with the aircraft fuselage. The stress distribution and deflection for each point of the wing structure is found for both isotropic and orthotropic material. Secondly, the optimum design (minimum weight) for both isotropic and orthotropic material is estimated. Two methods were used to find the optimum design of the wing structure. In the first method the MORPHING criteria was programmed and used as optimizer program in conjunction with ANSYS11 program as solver program, Ansys Parametric Design Language (APDL) is used to write the MORPHING method. In the second method, the ANSYS11 program is used for both analysis and optimization. The results found by using the first method show (22.7%) weight reduction for isotropic material and (23.2%) for orthotropic material. The result found from second method show (24.4%) weight reduction for isotropic material and (24.1%) weight reduction when using orthotropic material