Spline Variational Theory for Composite Bolted Joints

Abstract

A hybrid approximation model for predicting stresses and strains in open-hole composites was developed. This model is based on combined asymptotic and spline approximation stress functions and spline approximation displacement functions which provide accurate stress fields in the vicinity of the ply interface and the hole edge in a multilayered composite laminate. This hybrid model, using spline variational theory and Reissner's variational principle, provides directionally nonunique stress approximation critical for singular stress regions, combining it with flexibility of displacement approximation to analyze practical structures. Experimental studies of damage initiation and propagation in the open-hole laminates for three stacking sequences were performed. Theoretical strains obtained from the spline variational theory agree well with experimental strain measurements at low loadings prior to damage initiation.

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Document Details

Document Type
Technical Report
Publication Date
Jan 01, 1998
Accession Number
ADA351476

Entities

People

  • E. Iarve
  • R. Y. Kim

Organizations

  • University of Dayton

Tags

Communities of Interest

  • Air Platforms
  • Sensors

DTIC Thesaurus Topics

  • Acoustic Emissions
  • Air Force Research Laboratories
  • Bolted Joints
  • Composite Materials
  • Coordinate Systems
  • Elastic Properties
  • Laminates
  • Manufacturing
  • Materials
  • Measurement
  • Mechanical Properties
  • Stress Concentration
  • Stress Strain Relations
  • Stresses
  • Three Dimensional
  • Two Dimensional
  • Variational Principles

Fields of Study

  • Physics

Readers

  • Linear Algebra
  • Structural Health Monitoring of Composite Structures.