Research Studentships

Variable Amplitude Corrosion Fatigue of Offshore Wind Steel Foundation Structures

This project proposes to study the interaction between wind induced machine loading and wind/wave (environmental) loading acting on the support structure. Currently researchers and designers do not know if or when peak machine loads coincide with environmental loads and how these might interact. Fatigue and corrosion assisted fatigue damage is a local phenomenon and is driven by the interaction between residual and applied stresses locally. This means that machine loading may be contributing to peak stresses in certain parts of the structure and environmental loading contributing to stresses elsewhere. There will be inevitably circumstances where stresses from all sources combine and result in fatigue damage however, the degree to which this might happen and affects on damage need to be researched and better understood.

The EngD project will investigate temporal and spectral approaches to combining machine and wind loading induced fatigue stresses and to determine the sensitivity or otherwise of each approach to fatigue damage. It will also research and develop a "typical" or "standardised" loading sequence/spectrum so that fundamental corrosion fatigue damage mechanisms can be investigated at different laboratories without results being deemed as laboratory specific or machine (wind turbine) specific and conduct variable amplitude fatigue tests on crack propagation specimens under simulated service conditions to better understand the effects of load and frequency characteristics on crack propagation behaviour. This EngD would suit candidates with a background in mechanical, materials or structural engineering.
This is an EngD project within the Renewable Energy Marine Structures (REMS) Centre for Doctoral training (CDT). REMS is an EPSRC funded Centre for Doctoral Training set up to train fifty Engineering Doctorate and PhD students over an eight-year period. Interested applicants should send an up-to-date CV to Dr Ali Mehmanparast (a.mehmanparast@cranfield.ac.uk). The candidate will need to meet the academic requirements for enrolment for the EngD degree at Cranfield University; an upper second or first (or equivalent) in mechanical engineering or related discipline. Student eligibility criteria for EPSRC funding require a relevant connection with the UK, usually established by residence. EU students may be eligible for a fees-only award (i.e. no maintenance grant).

Reliability of condition monitoring technologies for offshore wind foundations under uncertainty

The use of sensors and condition monitoring (CM) technologies to collect continuous real time measurements on wind turbine foundations as a means of detecting the existence of damage, identifying the location of damage, assessing the type and severity of damage, and estimating the remaining useful life (RUL) has been significantly growing in recent years. Quite often, considerable errors are reported between the measured structural modal properties through inspection and the simulated results based on CM-base dataset due to various “uncertainties”. These uncertainties are usually related to design parameters, variable and complex offshore environments, complexity of the non-destructive testing (NDT) techniques, degree of detection of defects, etc. Neglecting the uncertainties involved in offshore wind structural monitoring may lead to collection of unreliable data and inaccurate evaluation of the system conditions, thereby inappropriate planning of inspection and preventative maintenance tasks. This project will provide an analytical reliability model to identify, analyse and evaluate the impacts of different types of uncertainties on condition assessment and monitoring of wind turbine foundation based on its sensor system, damage sensitive parameters, damage identification techniques, and system reliability index. The model will be then tested on a baseline offshore jacket platform structure and the probability of detection (POD), rate of false positive, true positive, false negative, and true negative are assessed.
This is an EngD project within the Renewable Energy Marine Structures (REMS) Centre for Doctoral training (CDT). REMS is an EPSRC funded Centre for Doctoral Training set up to train fifty Engineering Doctorate and PhD students over an eight-year period. Interested applicants should send an up-to-date CV to Dr Mahmood Shafiee (m.shafiee@cranfield.ac.uk). The candidate will need to meet the academic requirements for enrolment for the EngD degree at Cranfield University; an upper second or first (or equivalent) in Mechanical, Civil, Industrial engineering or related discipline. Student eligibility criteria for EPSRC funding require a relevant connection with the UK, usually established by residence. EU students may be eligible for a fees-only award (i.e. no maintenance grant).
of condition monitoring technologies for offshore wind foundations under uncertainty


Reliability of Integrity Monitoring for Offshore Wind Structures

The performance of traditional NDT is characterised in terms of Probability of Detection (POD) and Probability of Sizing (POS). The evaluation of these parameters is now widely understood and accepted. They provide a scientific and objective basis to compare systems and approaches. There is however, no equivalent basis for comparison of many Integrity Monitoring (IM) techniques. For example, these measures are completely inappropriate to describe the performance of stress monitoring equipment. In addition, traditional binomial statistics on which POD and POS are generally based, cannot address the improved confidence that a monitored result will have compared to a blind inspection. Uncertainty associated with relatively few inspection positions becomes much less of a problem as increasing amounts of pertinent information should mean increased confidence in defect detection and characterisation which will ultimately benefit the decision making/planning process.

This EngD study will aim to investigate the shortcomings or otherwise of current methods for describing the performance characteristics of NDT systems and how these might be developed to allow quantitative and scientific description of the performance characteristics of IM systems. This EngD would suit candidates with a background in inspection, monitoring, statistics, Electronic or Mechanical Engineering.

This is an EngD project within the Renewable Energy Marine Structures (REMS) Centre for Doctoral training (CDT). REMS is an EPSRC funded Centre for Doctoral Training set up to train fifty Engineering Doctorate and PhD students over an eight-year period. Interested applicants should send an up-to-date CV to Dr Ali Mehmanparast (a.mehmanparast@cranfield.ac.uk). The candidate will need to meet the academic requirements for enrolment for the EngD degree at Cranfield University; an upper second or first (or equivalent) in mechanical engineering or related discipline. Student eligibility criteria for EPSRC funding require a relevant connection with the UK, usually established by residence. EU students may be eligible for a fees-only award (i.e. no maintenance grant).


Corrosion Damage Effects on the Structural Integrity Assessment of Offshore Structures

An important issue to be considered in the structural integrity assessment of offshore structures, such as offshore wind turbines and Oil & Gas pipelines, is the characterisation of material degradation due to environmental damage and its subsequent effects on the remaining lifetime predictions. The main aim of this project is to investigate the importance of corrosion and corrosion-fatigue damage in the structural integrity assessment of offshore steel weldments (i.e. base metal, heat affected zone and weld metal) using experimental testing and numerical modelling techniques. S355 structural steel weldments, which are widely used in offshore industry, will be exposed to different corrosive environments for various durations and the corresponding changes in the mechanical response, fracture and fatigue crack growth behaviour of the material will be examined. Furthermore, a numerical model will be developed and validated to predict corrosion pitting, corrosion weight loss and corrosion-fatigue crack growth behaviour in S355 weldments in the seawater environment. This project is a joint collaboration between the Renewable Energy Marine Structures (REMS) Centre for Doctoral Training (www.rems-cdt.ac.uk) and the University of New South Wales (UNSW). The results from this project will be employed in the remaining life assessment of offshore structures and are expected to have an impact on reducing the inspection and maintenance costs for offshore structures by proposing a new design-for-purpose technique to improve the integrity of offshore welded structures.
This is an EngD project within the Renewable Energy Marine Structures (REMS) Centre for Doctoral training (CDT). REMS is an EPSRC funded Centre for Doctoral Training set up to train fifty Engineering Doctorate and PhD students over an eight-year period. Interested applicants should send an up-to-date CV to Dr Ali Mehmanparast (a.mehmanparast@cranfield.ac.uk). The candidate will need to meet the academic requirements for enrolment for the EngD degree at Cranfield University; an upper second or first (or equivalent) in mechanical engineering or related discipline. Student eligibility criteria for EPSRC funding require a relevant connection with the UK, usually established by residence. EU students may be eligible for a fees-only award (i.e. no maintenance grant). A strong background in fracture mechanics, materials behaviour, experimental testing and finite element modelling is required for this project.