Novel Photomechanics Approaches to Determine the Intra- and Inter-laminar Properties of Composites at High Rates of Strain

Abstract

This project aims at exploring news ways of testing composite materials at high rates. In particular, the project focuses on transverse tension and shear, both intra and interlaminar. It is well known that such properties are difficult to measure using Kolsky bars because of the relatively low wave speeds and low strains to failure, preventing quasi-static equilibrium to be achieved before failure. As a consequence, reliable available data only span up to a few 100s of s-1. Recently, progress in ultra-high speed imaging has allowed a new methodology to emerge. The underpinning idea is to use acceleration fields obtained by ultra-high speed imaging of grid or speckle patterns to provide stress information through mechanical equilibrium. Moreover, the implementation of inertial impact enables for free edge reflection of the impeding compression wave to be turned into tension, providing tensile properties (stiffness and strength) without the need for any gripping of the test specimen. This methodology has been termed Image-Based Inertial Impact (IBII). In this project, the IBII methodology has been adapted so far to the transverse tensile properties of carbon/epoxy UD composites, as well as to interlaminar tension. Strain rates in the range of 1000s of s-1 were achieved with exceptional quality data to measure the stiffness and strength. Future work will extend it to intra and interlaminar shear, and the combination of transverse tension and shear.

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Document Details

Document Type
Technical Report
Publication Date
Apr 12, 2019
Accession Number
AD1077583

Entities

People

  • Fabrice Pierron

Organizations

  • University of Southampton

Tags

Communities of Interest

  • Air Platforms
  • Energy and Power Technologies
  • Ground and Sea Platforms

DTIC Thesaurus Topics

  • Composite Materials
  • Fiber Reinforced Polymers
  • Glass Fibers
  • Laminates
  • Materials
  • Materials Laboratories
  • Materials Science
  • Materials Testing
  • Mechanical Properties
  • Mechanics
  • Modulus Of Elasticity
  • Polymer Matrix Composites
  • Static Tests
  • Tensile Properties
  • Tensile Testing
  • Test And Evaluation
  • Test Methods

Fields of Study

  • Materials science

Readers

  • Mechanical Engineering/Mechanics of Materials.
  • Structural Health Monitoring of Composite Structures.
  • Systems Analysis and Design