Comparative Structural Analysis of ERCO Ercoupe Wing Rib with Different CutOut Geometries

Abstract

The structural efficiency of aircraft components is important to enhance performance, weight reduction, and safety. The wing rib is one of these components that help in the maintenance of the airfoil shape, as well as passing the aerodynamic loads to the primary structural members. The paper under discussion is based on the structural investigation of a wing rib of the ERCO Ercoupe aircraft to examine how various cut-out shapes impact its performance. The wing rib design was based on a plane that was situated in the hangar and designed using CAD software. It was introduced with three cut-out patterns of circular, elliptical and rectangular to minimize the structural weight. Under the same loading and boundary conditions, Finite Element Analysis (FEA) was conducted to analyze the distribution of stress, deformation and strain features of each configuration. The findings revealed that the use of cutouts has a tremendous effect on structural behaviour of the wing rib. The rib with no cut-outs exhibited little deformation and stress, but was relatively heavier. The elliptical cut-out was one of the altered designs that had enhanced structural performance characterized by reduced stress concentration and controlled deformation. Conversely, the circular cut-out caused more deformation and stress, which implies that it was not as stiff when compared to the rectangular cut-out which had a localized stress in the corners. All in all, the research finds that cut-out geometry is an important aspect in the achievement of weight reduction and structural integrity. The cut-out shape is an elliptical shape which offers a good balance between strength and weight and is therefore the best design out of the cases under consideration. The results of this work help to create light and efficient aircraft constructions and form a basis of further optimization investigations.