Mitigating Stress Waves by using Nanofoams and Nanohoneycombs

Abstract

In this ARO project, we had a remarkable finding: In dynamic indentation test, the indentation size of a silica nanofoam was smaller than in a solid silica; i.e. the former was effectively harder than the latter. All the samples were in the same amorphous silica phase; the porosity of all nanofoam samples was approximately 60%, and therefore, their mass density was only approximately 40% of that of solid silica. The experiment was conducted in a Split Hopkinson Bar (SHB) setup. A titanium striker impacted on a steel incident bar at approximately 8.5 m/s; the incident bar forced a hard hemispherical indenter into the silica sample. The silica sample was sandwiched in between the indenter and a steel transmitted bar.

Open PDF

Document Details

Document Type
Technical Report
Publication Date
Feb 13, 2015
Accession Number
ADA626076

Entities

People

  • Yu Qiao

Organizations

  • University of California, San Diego

Tags

Communities of Interest

  • Energy and Power Technologies

DTIC Thesaurus Topics

  • Chemistry
  • Electron Microscopes
  • Engineering
  • Materials
  • Materials Processing
  • Measurement
  • Mechanical Working
  • Mechanics
  • Scanning Electron Microscopes
  • Shear Bands
  • Shear Strength
  • Shear Tests
  • Stainless Steel
  • Strain Rate
  • Stress Waves
  • Stresses
  • Students

Readers

  • Electrochemical Engineering/ Fuel Cell Technologies
  • Mechanical Engineering/Mechanics of Materials.
  • Surface Coatings Technology.