文档介绍：COMPOSITE
STRUCTURES
posite Structures 43 (1999) 257-274
Buckling and postbuckling behavior posite cross-ply laminates
with multiple delaminations
Woo-Min Kyoung, Chun-Gon Kim *, Chang-Sun Hong
Department of Aerospace Engineering, Korea Adtamed Institute of Science and Technology, 373-l Kusong-dong, Yusong-gu, Taejon, -701,
South Korea
Abstract
In this study, buckling and postbuckling analysis was conducted for posite cross-ply laminates with multiple delami-
nations pressive loading. The geometries of multiple delaminations are a one-dimensional through-the-width type and a
two-dimensional embedded circular type. In a nonlinear finite element formulation, the updated Lagrangian description and the
modified arc-length method were adopted. For a finite element modeling posite laminates, the eight-node degenerated shell
element was used. To avoid overlapping between delaminated areas, the contact node pair was defined by virtual beam element.
Numerical results showed that multiple delaminations lower buckling loads and load carrying capacities in the postbuckling region.
The buckling load varies with the projected area of the delaminations. However, the geometry of multiple delaminations has an
influence on the postbuckling behavior. The load carrying capacity differed with the distribution type due to the local reduction of
bending stiffness and the contact behavior of the sublaminates. 0 1999 Elsevier Science Ltd. All rights reserved.
Keywords: Delamination buckling; Multiple delaminations; Postbuckling behavior; Contact analysis; Composite laminate
Nomenclature 1. Introduction
a, length of the ith delamination The delamination is the interlaminar failure mode of
Zj( = a/L) normalized length of the ith delamina- composite materials, which is represented by the inter-
tion layer crack generated between laminae of the laminates.
Di diameter of the ith delamination Delaminations can be developed as a result of lo