Design and Manufacture of Stiffened Composite Panels

Abstract

The use of composite materials in aircraft primary structure is becoming more common. Stiffened composite panels have been designed for a variety of load carrying conditions in aircraft. In this study, design consideration and manufacturing techniques for J stiffened composite panels were reviewed and discussed. Cocuring manufacturing technique was used to produce stiffened composite panels. Ultrasonic Cscan inspection was carried out to detect any defects in the panels. A finite element method was used to predict buckling and the post-buckled loads of the stiffened panels. The experimental buckling loads, as well as the failure loads, were in good agreement with the analytical results. The strain data from the tests were also in close agreement with those predicted by analysis. The structural efficiencies of tested panels were determined and compared with the same aluminum configuration. This paper presents the details of tooling, manufacturing techniques and test results.

Structural Efficiency and Post-buckling Strength of J- and Hat-stiffened Composite Panels

“…They were then loaded in uniaxial compression under displacement control so that catastrophic failure in compression could be assessed. Based on the literature survey [4,14], the maximum out-of-plane displacement of the stiffened composite panel would likely occur in the center bay of the panel, near the mid-length. Thus, most of the strain gages were bonded to the mid-length area of the panel in order to capture critical strains in the buckled and post-buckled states.…”