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Study of Effective Stress Intensity Factor through the CJP Model Using Full-Field Experimental Data
Alonso Camacho-Reyes1, Jose Manuel Vasco-Olmo1, Giancarlo Luis Gómez Gonzales1
1Departamento de Ingeniería Mecánica y Minera, Universidad de Jaén, 23071 Jaen, Spain.
Materials (Basel, Switzerland)
|August 26, 2023
Summary
The Christopher-James-Patterson model effectively analyzes fatigue crack growth in titanium, separating stress factors to reveal crack-shielding phenomena. This model validates thermoelastic and digital image correlation data in fracture mechanics.
Area of Science:
- Materials Science
- Fracture Mechanics
Background:
- Fatigue crack growth is influenced by complex phenomena like crack closure and shielding.
- Accurate assessment of stress intensity factor ranges is crucial for predicting material fatigue life.
Purpose of the Study:
- To apply the Christopher-James-Patterson crack tip field model for analyzing effective stress intensity factor ranges.
- To investigate crack-shielding phenomena by separating the effective stress intensity factor into elastic and retardation components.
- To validate the model's efficacy using experimental data from thermoelasticity and digital image correlation.
Main Methods:
- Fatigue crack growth tests were conducted on Compact-Tension specimens of pure grade 2 titanium.
- Thermoelastic stress analysis and digital image correlation (DIC) were employed to measure data at various crack lengths.
- The Christopher-James-Patterson model was utilized to infer and assess effective stress intensity factor ranges.
Main Results:
- A strong agreement (approximately 2% average deviation) was observed between thermoelastic and DIC measurements.
- The Christopher-James-Patterson model demonstrated validity in analyzing fracture mechanics phenomena where plasticity is significant.
- The study highlighted the importance of crack-shielding effects beyond simple crack closure.
Conclusions:
- The Christopher-James-Patterson model provides a robust framework for rationalizing fatigue crack growth rates.
- The model's ability to differentiate elastic and retardation components aids in understanding crack-shielding mechanisms.
- Experimental validation confirms the model's utility in advanced fracture mechanics research.
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