A Multilayer, Traction-Free Edge, Quadrilateral, Warping Element for the Stress Analysis of Composite Plates and Shells.

摘要

A hybrid stress multilayer warping quadrilateral element with a traction-free edge (TFQE), based on the Principle of Modified Complementary Energy, has been developed for efficient finite element modeling and analysis at and near free edges. The assumed stress distributions in the element were selected so as to satisfy the basic equations of equilibrium; sufficient detail was implemented throughout each layer of each element to model the steep boundary layer stress gradients, including the important interlaminar stresses. The interlayer stress continuity and traction-free conditions at the free edge are satisfied exactly; the resulting stress distribution was examined for consistency as required by 3-dimensional stress functions. The stress assumption includes no singularity. The traction-free edge is allowed to warp freely.