Pressure Self-focusing Effect and Novel Methods for Increasing the Maximum Pressure in Traditional and Rotational Diamond Anvil Cells

Abstract

The main principles of producing a region near the center of a sample, compressed in a diamond anvil cell (DAC), with a very high pressure gradient and, consequently, with high pressure are predicted theoretically. The revealed phenomenon of generating extremely high pressure gradient is called the pressure self-focusing effect. Initial analytical predictions utilized generalization of a simplified equilibrium equation. Then, the results are refined using our recent advanced model for elastoplastic material under high pressures in finite element method (FEM) simulations. The main points in producing the pressure self-focusing effect are to use beveled anvils and reach a very thin sample thickness at the center. We find that the superposition of torsion in a rotational DAC (RDAC) offers drastic enhancement of the pressure self-focusing effect and allows one to reach the same pressure under a much lower force and deformation of anvils.

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Document Details

Document Type
Technical Report
Publication Date
Apr 21, 2017
Accession Number
AD1087686

Entities

People

  • Biao Feng
  • Valery I. Levitas

Organizations

  • Iowa State University

Tags

Communities of Interest

  • Space

DTIC Thesaurus Topics

  • Elastic Properties
  • Engineering
  • Equations
  • Geometry
  • High Pressure
  • Materials
  • Materials Science
  • Mechanical Engineering
  • Mechanics
  • Phase Transformations
  • Plastic Deformation
  • Plastic Flow
  • Plastic Properties
  • Pressure Distribution
  • Pressure Gradients
  • Two Dimensional
  • Yield Strength

Fields of Study

  • Physics

Readers

  • Finite Element Method (FEM) for solving Partial Differential Equations (PDEs)
  • Mechanical Engineering/Mechanics of Materials.