Mechanical Properties of a Tapered Composite Structure in a Movable Aircraft Wing

Tapered laminate structures with ply drop-off are used extensively in aeronautic and astronautic applications. However, ply drop-off involves inherent structural discontinuities that create stress concentrations, potentially resulting in failure below the loading capability of the structure. We performed experiments to study the mechanical properties of a tapered laminate structure in the movable wing skin of an aircraft, and examined the effects of fatigue and damp-heat exposure on such properties. The mechanical behavior and failure modes of the structure were simulated using finite element analyses and compared with the experimental results. The experimental findings were found to agree satisfactorily with the simulation results. This study provides useful information to support the design and production of such composite structures.