Analysis of fiber-reinforced composite plates utilizing curvilinear fiber trajectories

Abstract

Four plates with centrally located circular holes were manufactured using a fiber placement technique. With two plates the fibers were steered around the holes in curvilinear trajectories. With the two other plates the fibers were placed in the conventional straight line format. For the case of the curvilinear trajectories, the fibers were continuous from one end of the plate to the other, whereas for the straight trajectories the fibers were cut by the presence of the hole. Two plates, a curvilinear fiber plate and a straight fiber plate, were tested in tension. The two other plates were tested in compression. The straight fiber plates were considered as baseline cases. Since the plates were thin, compression testing resulted in buckling and post buckling. The current work focuses on the analysis of these four plates and a comparison between the analysis and experimental results. Because of a spatial dependence of the A and D stiffness matrices for the curvilinear fiber cases, the analyses were conducted using finite element methods, and included a failure criterion. A scheme to improve the plate design is also considered.