Buckling of Unidirectional Composites Containing Noncircular Fibers: Part I—Elliptical Sections

Abstract

A micro-macro approach is developed to study the critical buckling stress of unidirectional composite laminates containing continuous fibers with circular or noncircular shape in cross section. The fiber volume fraction of the laminates, the slanted angle of the noncircular fibers and the distribution probability of the slanted angle are taken into consideration. The method of solutions is generally derived for unidirectional composites containing noncircular fibers of any shape. In particular, solutions are given for laminates containing circular fibers or elliptical fibers in part 1 of these papers. The solution of laminates containing elliptical fibers shows that the critical buckling stress can be either better or worse than that containing circular fibers under certain conditions. Parametric studies are presented to reveal the important factors associated with the critical buckling stress problem.