Testing and analysis of downscaled composite wing box

Abstract

The fabrication, bending test, and analysis of a downscaled composite wing box were presented. Before the fabrication of the downscaled composite wing box, an I-stiffened composite plate, which was made by the same layup method as the skin of the wing box, was tested and analyzed. The graphite/epoxy wing box consisted of two cocured parts. One part had a lower skin and two I stiffeners. The other part had an upper skin, two I stiffeners, and twospars, The mold for the cocuring of the composite wing box and bending test machine of the wing box were designed and manufactured, In the bending test, the buckling mode of the upper skin was observed by a Moire technique and compared with finite element analysis. The bending behavior of the wing box was investigated by the experiment and the finite element analysis. A good correlation between test and analysis was obtained for the bending behavior of the downscaled composite wing box.