Stress distribution in diametral compression tests

Area of Science:

• Solid Mechanics
• Materials Science
• Computational Engineering

Background:

• Experimental studies show a strong correlation between loaded area extension and fracture load.
• Understanding the underlying mechanics of fracture initiation is crucial for material design and failure analysis.

Purpose of the Study:

• To investigate the stress distribution in diametral compression tests using the finite element method.
• To explain the experimentally observed relationship between loaded area and fracture load.

Main Methods:

• Finite element method (FEM) analysis was employed.
• Stress distribution in a circular specimen's quadrant was studied.
• Variations in contact surface width were analyzed at a constant load distribution.

Main Results:

• Below a critical contact surface width, peripheral tensile stresses emerged outside the contact area.
• These peripheral tensile stresses exceeded central stresses, potentially initiating fracture.
• Changes in central tensile stresses had minor impact compared to peripheral stresses.

Conclusions:

• Peripheral tensile stresses are a critical factor in fracture initiation during diametral compression tests.
• This explains why the extension of the loaded area influences the fracture load.
• Material fracture behavior is significantly influenced by stress concentrations at the periphery of the loaded zone.