qIn this study, a combination of experiments and analyses are performed to characterize the structural response of two variable stiffness composite panels to a series of thermal and mechanical loads. This characterization covers all phases of the structures lifetime from design through global failure. These panels are advanced composite structures in which the fiber orientation angle varies continuously as tows are laid down along predefined curvilinear paths within each ply. The panels are manufactured from AS4/977-3 graphite-epoxy prepreg using an advanced tow placement system. Both variable stiffness panels have the same nominal layup, but one panel (the panel with overlaps) has overlapping tow bands of varying thickness and the other panel (the panel without overlaps) has a theoretically uniform-thickness laminate. A conventional uniform-thickness panel with a straight-fiber 5s layup (the baseline panel) is also evaluated to provide a reference for comparison of the variable stiffness panel performance.qEach of the three composite panels is subjected to several thermal cycles where the unconstrained panels are heated from room temperature to a maximum of 150 degrees Fahrenheit (abbreviated as AdF or deg. F). ln this section, the testanbsp;...
|Title||:||Thermal and Structural Performance of Tow-placed, Variable Stiffness Panels|
|Author||:||Kingsley Chauncey Wu|
|Publisher||:||IOS Press - 2006-01-01|