E-Thesis 103 views
Long-Term Environmental Stability of Hybrid Organic Matrix Composite Driveshafts and their Non-Corrosion Resistant Steel Interfaces / WILLIAM JARRETT
Swansea University Author: WILLIAM JARRETT
DOI (Published version): 10.23889/SUThesis.68933
Abstract
In the aerospace industry, the drive towards more efficient gas turbine engines has led to the exploration of hybrid material systems, blending the resilience of metals with the composite lightness. Organic Matrix Composites are pivotal in this regard, offering weight reductions over traditional all...
| Published: |
Swansea University, Wales, UK
2024
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| Institution: | Swansea University |
| Degree level: | Doctoral |
| Degree name: | Ph.D |
| Supervisor: | Jeffs, S. |
| URI: | https://cronfa.swan.ac.uk/Record/cronfa68933 |
| Abstract: |
In the aerospace industry, the drive towards more efficient gas turbine engines has led to the exploration of hybrid material systems, blending the resilience of metals with the composite lightness. Organic Matrix Composites are pivotal in this regard, offering weight reductions over traditional all-metal components. Integrating these composites into engine designs, however, and particularly in regions experiencing variable hygrothermal conditions, introduces complex challenges associated with material degradation, especially at the interfaces where dissimilar materials meet. Corrosion at these interfaces, catalysed by moisture ingress and fluctuating temperatures, poses a significant threat to the structural integrity and operational efficiency of engine components. The interface between the organic composite and metal fixings is particularly vulnerable, as the differing material properties can lead to stress concentrations, accelerated wear, and eventual mechanical failure under operational loads. This degradation process is exacerbated in the cooler, humid sections of the engine where condensation is more prevalent, creating ideal conditions for corrosive processes to initiate and propagate. This thesis investigates the specific mechanisms of failure associated with these hybrid driveshafts and develops testing methods to quantify the effects of corrosion on the interface. Utilising sinusoidal and microsplined driveshaft samples provided by Rolls Royce plc, this study aims to compare the interfacial resilience across different shaft designs under similar operational conditions. Recognising the slow nature of environmental degradation under normal conditions, the study employs accelerated moisture uptake and thermal/pressure testing to simulate extended operational life within a condensed timeframe. These accelerated tests aim to mimic harsh conditions, providing vital insights into the long- term durability and reliability of the hybrid material systems. By examining distilled and saltwater uptake into the driveshaft composite, the research shows how different environmental conditions influence corrosion pathways to the interface. Furthermore, thermal testing under elevated pressures is conducted to replicate potential end-of-life scenarios, revealing significant microcracking and delamination at the composite interfaces. These findings lay a crucial foundation for enhancing the lifecycle management of composite driveshafts, with implications for designing more robust and durable hybrid material systems for future aerospace applications. |
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| Item Description: |
A selection of content is redacted or is partially redacted from this thesis to protect sensitive and personal information |
| Keywords: |
Hybrid Driveshaft, Corrosion, Organic Matrix Composite, Novel Tensile Testing |
| College: |
Faculty of Science and Engineering |
| Funders: |
Rolls Royce plc |