Study of Composite Material Failure Under Tensile and Cyclic Loading

Abstract

Composite structures continue to gain popularity in engineering applications as they offer great strength to weight ratios, design flexibility and can last a long time. However, they are not exempt from catastrophic failure and fail without warning. Unlike metals, composites do not have defined endurance limits or established S-N curves, and their failure mechanism under cyclic loading is still largely underdeveloped. This thesis aimed to use a multiscale approach to predict the residual strength of glass fiber composites (GFC) after cyclic loading, create an S-N curve for GFC and glass fiber bundles (GFB) and assess recently proposed universal failure criteria for notched specimens. GFC and GFB specimens' behavior were analyzed under tensile and cyclic loading. Polymethyl methacrylate (PMMA) and laminated carbon fiber composites (CFC) with cross-ply (CP) and quasi-isotropic (QI) orientations containing various notch shapes were tensile tested and analyzed in Ansys. As a result, a probabilistic model for residual strength after cyclic loading for GFC was created and agreed with the experimental data. Additionally, S-N curves were generated for GFC and GFB. The results of the proposed failure criteria also agreed very well against experimental data for the materials tested with various notch types.

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Document Details

Document Type
Technical Report
Publication Date
Mar 01, 2022
Accession Number
AD1173268

Entities

People

  • Carlos J. Diaz-colon

Organizations

  • Naval Postgraduate School

Tags

Communities of Interest

  • Air Platforms
  • Ground and Sea Platforms
  • Space

DTIC Thesaurus Topics

  • Carbon Fibers
  • Composite Materials
  • Composite Structures
  • Engineering
  • Failure Mode And Effect Analysis
  • Fiber Reinforced Composites
  • Fracture (Mechanics)
  • Glass Fibers
  • Laminates
  • Materials
  • Materials Laboratories
  • Materials Science
  • Materials Testing
  • Mechanical Engineering
  • Mechanics
  • Modulus Of Elasticity
  • Probabilistic Models
  • Tensile Strength

Fields of Study

  • Materials science

Readers

  • Educational Psychology
  • Structural Health Monitoring of Composite Structures.