Mitigating Stress Waves Using Nanofoams and Nanohoneycombs

Abstract

(1) In the past 10 months, we conducted quasi-static shear tests and SHB dynamic tests on single-parameter silica foam samples. The testing data showed consistent correlation between the cell size and the transmitted pulse pressure and energy: Reducing cell size to below 100-200 nm has a significant beneficial effect on promoting energy absorption. To achieve the above result, we also (2) Further improved the SHB testing system, and developed single-pulse momentum trapper; (3) Developed a quantitative SEM image analysis technique to precisely identify shear bands, compression zones, and undamaged zones in tested samples. (4) Synthesized two-parameter silica foam samples, with the cell size ranging from tens of nm to a few micrometers and the porosity ranging from approximately 60% to approximately 80%. (5) Performed quasi-static shear tests and SHB dynamic tests on two-parameter silica foam samples. The testing data, although interesting, are non-conclusive, as the influences of cell size and porosity cannot be separately analyzed. (6) Developed new approaches and synthesized one-parameter silica foam samples, which had nearly identical porosity but different cell sizes from tens of nm to more than 1 micro meters. (7) Quantitative SEM image analysis of one-parameter samples is being performed.

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Document Details

Document Type
Technical Report
Publication Date
Apr 16, 2014
Accession Number
ADA623574

Entities

People

  • Yu Qiao

Organizations

  • University of California, San Diego

Tags

Communities of Interest

  • Energy and Power Technologies

DTIC Thesaurus Topics

  • Absorption
  • Abstracts
  • Cell Size
  • Compression
  • Dynamic Tests
  • Engineering
  • Materials
  • Momentum
  • Peak Values
  • Porosity
  • Shear Bands
  • Shear Strength
  • Shear Tests
  • Stress Waves
  • Stresses
  • Structural Engineering
  • Waves

Readers

  • Combustion science or combustion engineering.
  • Explosive Engineering.
  • Fluid Dynamics.