Comparison of 2D Finite Element Modeling Assumptions with Results from 3D Analysis for Composite Skin-Stiffener Debonding

Abstract

The influence of two-dimensional finite element modeling assumptions on the debonding prediction for skin-stiffener specimens was investigated. Geometrically nonlinear finite element analyses using two-dimensional plane-stress and plane-strain elements as well as three different generalized plane-strain type approaches were performed. The computed skin and flange strains, transverse tensile stresses and energy release rates were compared to results obtained from three-dimensional simulations. The study showed that for strains and energy release rate computations the generalized plane-strain assumptions yielded results closest to the full three- dimensional analysis. For computed transverse tensile stresses the plane-stress assumption gave the best agreement. Based on this study it is recommended that results from plane-stress and plane-strain models be used as upper and lower bounds. The results from generalized plane-strain models fall between the results obtained from plane-stress and plane-strain models. Two-dimensional models may also be used to qualitatively evaluate the stress distribution in a ply and the variation of energy release rates and mixed mode ratios with delamination length. For more accurate predictions, however, a three-dimensional analysis is required.

Open PDF

Document Details

Document Type
Technical Report
Publication Date
Sep 01, 2002
Accession Number
ADP023577

Entities

People

  • Isabelle L. Paris
  • Pierre J. Minguet
  • Ronald Krueger
  • T. K. O'brien

Organizations

  • Langley Research Center

Tags

Communities of Interest

  • Air Platforms

DTIC Thesaurus Topics

  • Composite Materials
  • Composite Structures
  • Delamination
  • Failure Mode And Effect Analysis
  • Finite Element Analysis
  • Laminates
  • Materials
  • Materials Testing
  • Mechanics
  • Numerical Analysis
  • Shape
  • Tensile Strength
  • Tensile Stress
  • Test Methods
  • Three Dimensional
  • Tilt Rotor Aircraft
  • Two Dimensional

Readers

  • Finite Element Method (FEM) for solving Partial Differential Equations (PDEs)
  • Materials Science (Mechanical Engineering).
  • Structural Dynamics.