Optimization of Variable Thickness and Stiffness Composite Plate Buckling Load Using FEM andSemi-Analytical Method

Abstract

In this study we report results on the manufacturing and response of cylindrical sandwich panels subjected to axial compressive loads. The structural panels were manufactured using Out-of-Autoclave (OOA) carbon fiber composite face sheets and aluminum hex core, using Automated Fiber Placement (AFP) manufacturing. Two types of panels were manufactured: pristine panels with straight fiber paths, and steered fiber panels, to examine the influence of fiber steering, gaps and overlaps on the compressive buckling response. Panel testing used specially designed fixtures, and digital image correlation (DIC) for diagnostics along with point wise out of plane displacement measurements using a laser scanning system. Test results indicated that sandwich panels failed due to skin compressive failure leading to disbonding, rather than global panel buckling. Steered panels showed marginal decrease in strength.