Buckling Analysis of Tapered Composite Beams using a Higher Order Finite Element Formulation

Abstract

Tapered composite beams are increasingly being used in various engineering applications such as helicopter yoke, robot arms, and turbine blades. In the present work, the buckling analysis of laminated tapered composite beams is conducted using a higher order finite element formulation. In tapered laminates, the material and geometric discontinuities at ply drop-off locations lead to significant discontinuities in stress distributions. Higher order formulation ensures the continuity of the stress distribution through the thickness of a laminate as well as across the element interfaces, which is very important for the analysis of tapered laminates. In addition, higher order finite element formulation requires lesser number of elements in order to achieve reasonably accurate results in buckling analysis. The stiffness coefficients of the tapered laminated beam are determined in the present work based on the stress and strain transformations and the classical laminate theory. A detailed parametric study on various types of tapered composite beams is conducted.