Damage characterization of red sandstones using uniaxial compression experiments.

Area of Science:

• Materials Science
• Mechanical Engineering
• Solid Mechanics

Background:

• Material damage assessment is crucial for structural integrity.
• Existing methods for characterizing material damage have limitations.
• Acoustic emission (AE) and crack volume strain offer potential insights into damage evolution.

Purpose of the Study:

• To propose calculation formulae for damage variables using four distinct methods.
• To analyze the correlation between damage variables derived from AE, crack volume strain, damage statistic constitutive model, and dissipation energy.
• To identify the most effective method for pinpointing the damage strength point.

Main Methods:

• Development of calculation formulae for damage variables based on AE, crack volume strain, damage statistic constitutive model, and dissipation energy.
• Comparative analysis of damage variable evolution curves against strain.
• Identification of inflection points and damage strength points in the curves.

Main Results:

• Damage variables from all four methods show positive correlation.
• AE signals indicate the damage strength point precedes significant crack formation.
• Crack volume strain shows the largest damage variable values and high consistency with AE.
• Dissipation energy is the most effective method for identifying the damage strength point.

Conclusions:

• The four proposed methods for characterizing damage variables are interconnected.
• Acoustic emission and crack volume strain are closely related parameters for damage assessment.
• Dissipation energy provides a reliable indicator for identifying the material's damage strength point.