Evaluation of the Structural Integrity of Full-Scale Wing of Aerial Vehicle

Abstract

This paper describes the details of an experimental investigation focusing on the structural integrity and evaluates the structural characteristics like strain and deformation of the full-scale composite wing of aerial vehicle. The structural testing of composite wing is greatly influenced by the size of the structure, nature of loads, and boundary conditions at the supports. It is conventional to assume span-wise aerodynamic load distribution for aerial structure of typical aspect ratio, i.e., between 10 and 15. Apart from the span-wise load distribution on the wing, the other important parameters like chord-wise distribution of load, angle of attack at which the primary composite structure to be tested, the landing gear loads at the wing, and engine interfaces need to be simulated during the test. Generally, wing structures are tested for the worst case in terms of combined lift and drag which simulates the worst bending and twisting loads of the flight envelope. Care should be taken for distributing the lumped loads at desired locations; else it could lead to local stress concentration and local failure of the structure. In most of the structural tests, shear and bending will be captured, but twisting needs special attention in distributing the loads at spar/rib locations without altering the center of pressure of the aerodynamic load distribution. Adequacy of the test rigs and proper simulation of all attachments are addressed. The design and implementation of the structural integrity test along with experimental results are presented.