Strength analysis and optimisation of double-toroidal anvils for high-pressure research

Area of Science:

• Materials Science
• High-Pressure Physics
• Computational Mechanics

Background:

• The Paris-Edinburgh press is crucial for neutron scattering experiments requiring high pressures.
• Repeated failures of the double-toroidal anvil and gasket assembly at ~240 tonnes limit experimental capabilities.
• Existing models lack material property data for extreme high-pressure conditions.

Purpose of the Study:

• To investigate the failure mechanism of the double-toroidal anvil and gasket assembly.
• To develop a new modeling approach for opposed anvil devices under extreme stress.
• To identify design modifications for enhancing anvil performance and operational pressure.

Main Methods:

• Finite element method (FEM) for stress and deformation analysis.
• Utilized experimental data for simulation validation in the absence of high-pressure material properties.
• Modeled the large sample volume double-toroidal anvil and gasket assembly.

Main Results:

• Failure of the anvil assembly occurs at the surface.
• Tensile stress on the anvil surface is identified as the primary cause of failure.
• Stress distribution within the anvils was analyzed.

Conclusions:

• The current anvil design is susceptible to failure due to surface tensile stress.
• Optimized anvil designs can potentially extend the operational pressure range of the Paris-Edinburgh press.
• The developed modeling approach provides a validated method for analyzing extreme stress conditions.