BOEING 777 - 300ER WING STRUCTURAL ANALYSIS

CONCEPT
The aim of this project is to verify aircraft wing integrity by applying structural and fatigue analysis to the reference aircraft, and optimizations are addressed by considering alternative materials and aerodynamic improvements. Structural analysis is used not only to verify safety but also to guide changes that enable the aircraft to operate beyond its original useful life.

DESIGN/ANALYSIS
The aircraft wing model was created using the Abaqus CAE software based on the shape specifications provided by the manufacturer and approximations made throughout the analysis. It is then subjected to static FEM and the FEA results were manually validated with analytical equations. Some of the assumptions made include:
- The wing is a cantilever beam under load.
- The lift force is modeled as a uniformly distributed load in order to use the cantilever beam theory to perform analytical and numerical comparisons
- Bending occurs only span-wise.
- Torsion and bending chord-wise are ignored because they are negligible.
- The stress concentration factor is zero, i.e., the structure is perfect with no voids.
- The material of the wing is homogenous and isotropic (assume non-composite material).

RESULTS
The results of the static analysis are different because the FEA calculated the von Misses stress, and the manual calculation assumed that only bending stress exists along the span. This assumption ignores the effects of spanning twists due to the asymmetric shape of the wing and the shear stress due to drag. The effect of these loads on the equivalent stress is significantly lower than the calculated bending stress, but this deviation still occurs.
Material optimization was evaluated, and it was found that composites can significantly improve aircraft efficiency by reducing weight while maintaining the required mechanical properties.
Aerodynamic optimization was also evaluated by examining the use of winglets, which were found to improve aerodynamic performance. The reason for this is that the tip vortex is reduced. This reduces drag and improves efficiency.