A theoretical and computational framework for studying creep crack growth.

Area of Science:

• Materials Science
• Solid Mechanics
• Fracture Mechanics

Background:

• Steady-state creep is a critical phenomenon in material degradation under sustained load.
• Understanding crack growth under creep is essential for predicting component lifespan.
• Existing models may not fully capture the complex fracture processes ahead of a crack tip.

Purpose of the Study:

• To develop a theoretical framework for analyzing crack growth under steady-state creep.
• To propose a new class of damage zone models for fracture process simulation.
• To establish analytical and computational models for pure mode-I crack growth.

Main Methods:

• Power-law creep constitutive behavior for bulk material.
• Traction-separation rate law for damage zone modeling.
• Analytical modeling using $$-integral and dimensional analysis.
• Finite Element Method (FEM) for computational framework.

Main Results:

• Developed analytical models for steady-state crack growth in DCB specimens.
• Calibrated analytical models against detailed FEM simulations.
• Showed that only one dimensionless quantity $$ is needed for model determination.
• Investigated crack growth response in limits of small and large $$.

Conclusions:

• The proposed theoretical framework provides a fundamental model for creep crack growth.
• Parameters within the models can be determined from experimental data (creep deformation, rupture, crack growth).
• The study offers a robust approach for analyzing and predicting material behavior under creep conditions.