Thesis
High cycle fatigue and crack arrest analysis of components with compressive residual stress
- Creator
- Rights statement
- Awarding institution
- University of Strathclyde
- Date of award
- 2024
- Thesis identifier
- T17094
- Person Identifier (Local)
- 202062029
- Qualification Level
- Qualification Name
- Department, School or Faculty
- Abstract
- This thesis presents a method based on fracture mechanics to predict the high cycle fatigue life of structures with induced compressive residual stress and to calculate the minimum autofrettage pressure required to achieve crack arrest. For high cycle fatigue life assessment, the total fatigue life of a component is calculated as the sum of crack initiation life and crack propagation life. Three finite element models are included in the proposed method. In the first model, the residual stress distribution is determined using the tested monotonic stress strain curve of the material. The second model simulates crack propagation, where the crack propagation life is evaluated by superimposing the applied load and residual stress fields. In the third model, an equivalent stress amplitude is calculated based on mean stress correction and applied to obtain the crack initiation life from a stress crack initiation life curve, generated based on an assumed crack initiation length. For crack arrest analysis, these three models are employed to determine an effective stress intensity factor. Crack arrest is the n defined by comparing the effective stress intensity factor with the thresholds of crack propagation from various models. Finally, the minimum autofrettage pressure required to cause crack arrest is determined under a given working load cycle. Two types of double notched specimens made from 316L stainless steel and S355 low carbon steel are investigated to validate the accuracy of the proposed method. Numerical results show good agreement with experimental observations for both fatigue life prediction and crack arrest analysis. The proposed method is also applied to practical components from literature, demonstrating good applicability in the design of pressure vessels, valves, and pipes.
- Advisor / supervisor
- Nash, David
- MacKenzie, Donald
- Resource Type
- DOI
Relations
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PDF of thesis T17094 | 2024-10-14 | Public | Download |