A Generalized Plane Stress Theory of Microstructure: Application to Cross-Ply Laminates.

Abstract

A previous report by the authors developed a two-dimensional theory of microstructure for angle-ply laminates. Only in-plane loads were considered, and the laminate was assumed to be in a generalized plane state of stress. The present paper explores the application of the theory to cross-ply laminates. A simple example -- the free boundary problem of a homogeneously strained laminate-is used to illustrate theory and evaluate its accuracy. Comparison of the results with a reference solution (obtained by the finite element method) shows that stresses, with two exceptions, display the same degree of correlation that was obtained for the angle-ply construction. Unfortunately, one of the exceptions is the interlaminar normal stress at the middle plane of the laminate, which is considered to have a major influence on delamination failure of the material. It is argued that the discrepancies can be eliminated only by abandoning the generalized plane stress assumption, and admitting bending deformation of the individual layers. (Author)

Document Details

Document Type
Technical Report
Publication Date
Jul 01, 1975
Accession Number
ADA020660

Entities

People

  • Bill Moustakakis
  • Jaan Kiusalaas

Organizations

  • Pennsylvania State University

Tags

Communities of Interest

  • Air Platforms

DTIC Thesaurus Topics

  • Accuracy
  • Boundaries
  • Composite Materials
  • Construction
  • Construction Materials
  • Delamination
  • Finite Element Analysis
  • Laminates
  • Materials
  • Microstructure
  • Two Dimensional

Readers

  • Reinforced Composite Materials
  • Structural Dynamics.
  • Theoretical Analysis.