- Title
- Quantify the shift in critical strain energy density for a dynamic loaded S355J2 weld section by small punch testing
- Creator
- Snyman, Ross
- Subject
- Materials -- Testing
- Subject
- Materials -- Microscopy
- Subject
- Mechanical engineering
- Date Issued
- 2024-04
- Date
- 2024-04
- Type
- Master's theses
- Type
- text
- Identifier
- http://hdl.handle.net/10948/64830
- Identifier
- vital:73927
- Description
- The potential of using “critical strain energy density” as an indicator to detect material degradation on fatigue-loaded components, where the stress amplitude was gradually increased, was investigated by applying the small punch test methodology. Small punch discs were extracted from four fatigue specimens. Discs were extracted from two zones within the fatigue specimens: the heat-affected zone of a shield metal arc welded butt joint, as well as from parent metal plate area. Each fatigue specimen having been exposed to a different stress amplitude but equal number of fatigue cycles of 20 million. This allowed the development of a Small Punch Test results database, permitting the calculation of material properties by using a Finite Element Analysis inverse method. Critical strain energy values did not reveal any conclusive shift or correlation for discs extracted from the HAZ. This is mainly attributed to variance in the grain structure for HAZ samples. For discs extracted from parent metal, a decreasing trend in strain energy density value was noted in relation to an increase in the fatigue test stress amplitude. This observed change was a clear indication of the potential for using “Strain Energy Density”, as extracted from this test methodology, as a ranking tool for quantifying the extent of degradation of in-service components. The application of this study demonstrated the ability to monitor and predict material degradation for a given stress range over the expected life of a cyclically loaded component utilizing strain energy density results. This is useful, particularly in heavy industries where structures and large-scale components are used beyond their original design life.
- Description
- Thesis (MEng) -- Faculty of Engineering, the Built Environment, and Technology, School of Engineering, 2024
- Format
- computer
- Format
- online resource
- Format
- application/pdf
- Format
- 1 online resource (137 pages)
- Format
- Publisher
- Nelson Mandela University
- Publisher
- Faculty of Engineering, the Built Environment, and Technology
- Language
- English
- Rights
- Nelson Mandela University
- Rights
- All Rights Reserved
- Rights
- Open Access
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| Thumbnail | File | Description | Size | Format | |||
|---|---|---|---|---|---|---|---|
| View Details Download | SOURCE1 | Snyman, R.pdf | 7 MB | Adobe Acrobat PDF | View Details Download |