Analytical Modeling of ASTM Lap Shear Adhesive Specimens

Abstract

Advanced composite materials have been widely used in the aviation industry due to their lightweight and high-corrosion resistance. While the aviation industry increasingly uses adhesive bond for airframe composite structures, two issues have become particularly important: certification of adhesives used and certification of adhesive joints. A generally agreed-upon design methodology for adhesive-bonded composite joints, especially the failure criterion, is lacking. Typically, three failure modes of adhesive-bonded composite joints exist: (1) adherend failure, (2) adhesive failure (failure at the adhesive/adherend interface), and (3) cohesive failure (failure within the adhesive layer). A previous report (DOT/FAA/AR-0l/57, 2001) included an analytical model development for adherend failure mode. This report describes the investigation of adhesive and cohesive failure modes. The first part presents the derivation of an analytical model for predicting adhesive stress distribution within the joint specimens of ASTM D 3165. Elastic orthotropic adherends and elastic-perfectly plastic adhesive were used in the model development. The developed stress model was verified with finite element models by comparing the adhesive stress distributions. Failure analysis was conducted based on three failure criteria. Predicted strengths were compared with test data. The second part of the report contains finite element approaches for analyzing adhesive and cohesive failure modes. The equivalent plastic strain and J-integral were used as the failure criteria for cohesive and adhesive failure modes, respectively. Experimental data were used to establish the values of the equivalent plastic strain and the critical value of J-integral. (12 tables, 62 figures, 27 refs.)

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Document Details

Document Type
Technical Report
Publication Date
Feb 01, 2003
Accession Number
ADA413663

Entities

People

  • Charles Yang
  • John S. Tomblin
  • Zhidong Guan

Organizations

  • Wichita State University

Tags

Communities of Interest

  • Air Platforms

DTIC Thesaurus Topics

  • Composite Materials
  • Failure Mode And Effect Analysis
  • Finite Element Analysis
  • J Integrals
  • Laminates
  • Materials
  • Materials Science
  • Materials Testing
  • Mechanical Properties
  • Mechanics
  • Micromechanics
  • Modulus Of Elasticity
  • Shear Modulus
  • Stress Concentration
  • Stress Strain Relations
  • Stresses
  • Two Dimensional

Fields of Study

  • Engineering

Readers

  • Materials Science (Mechanical Engineering).
  • Surface Coatings Technology.