University West is offering a PhD studentship in Production Technology-Full Wave Inversion methodology based on ultrasonic data and applied to reconstruct dendrite orientations in anisotropic welds.

For a number of years many industries have struggled with materials that have been difficult to address with in-service inspections with non-destructive testing, NDT. This due to the fact that the components have shown strong anisotropic ultrasonic behaviour (weld in stainless material), i.e. unpredictable ultrasonic wave paths. Experience of modelling and verification against anisotropic material suggests that even extensive studies could not produce a statistical based model that could predict the anisotropic behaviour. A methodology to estimate the crystal orientations in an anisotropic weld was developed in a previous PhD project. The objective for this project is to develop a complete measurement system of dendrite orientation in a weld based on conventional ultrasonic technique applied in a new context.

The Scientific Project

The basic idea is to use ultrasonic based information to determine the dendrite orientation in a welded geometry. The information of dendrite orientation can then be used in modelling the specific weld for parameter studies in terms of optimal ultrasonic technique and also in order to solve the inverse problem. The project involves the development of a model of wave bending in the welding volume as a function of the orientation of anisotropic (dendrites). In addition, a measurement procedure for the measurement of the sound pathways through a corresponding welding volume is generated. The model, together with the measurement data, are then the basis in an optimization scheme that iterates the dendrite orientation of the real weld. Based on a simplified discretized model of the welding geometry develop a simple model of ultrasonic waves bending throughout the weld. Used inspection methodology shall be used as true values in an inverse scheme with experimental validation of the developed model against data, admitted to well-specified test blocks.

The practical validation of the developed model will be against data, retrieved from inspection of well-specified test blocks. These have previous been analysed in a previous project (ULiAS Task 4) but must be supplemented with the measurement technique developed in the project.

Doctoral degree program: Production Technology

Research centre: Doctoral students in Production Technology become members of the research group PTW (Production Technology West), The group collaborates with the engineering industry in the region at the Production Technology Centre, which houses an advanced research laboratory. For more information about our research centre visit our website here!

Job description:

The research program includes, in addition to participation in third-cycle courses and other activities, implementation of an independent thesis work. Doctoral students shall primarily devote themselves to their own education. A doctoral student may, however, be engaged to a limited extent in education, research and administration, mainly within Production Technology. Such duties, before a doctorate has been conferred, may not occupy more than 20 per cent of full-time working hours. (Higher Education Ordinance (SFS 1993:100) Chapter 5 section 2).

Qualification requirements:

To qualify for the position, two eligibility requirements must be met: 1) basic eligibility and 2) special eligibility.

1. The basic eligibility requirements for doctoral programs as set out in the Higher Education Ordinance are as follows: a degree at master’s level, completed courses totalling at least 240 university credits of which a minimum of 60 at master’s level or substantially equivalent knowledge gained in some other way whether in Sweden or abroad.
   
   
2. To fulfill the special eligibility requirements for a doctoral degree in Production Technology, a student must hold a degree at master’s level in a subject relevant to the doctoral degree subject. This degree may be in Applied Physics, Engineering Mathematics, Engineering Physics or equivalent, with a thesis project corresponding to at least half a year of study. The eligibility requirements may be fulfilled by studies in Sweden or abroad.

These qualification requirements have to be fulfilled at the time when the application is submitted. For more information please read 3.1 and 3.2 in General syllabus for the third-cycle programe in Production Technology, Ref. No U 2021/160.

To be successful in this project the applicant should be highly motivated, have an accurate way of working, and have good communicative and collaborative skills. The applicant should have a strong aptitude for analysis and problem solving of physical problems that relates to industry. In the selection process interviewing, referencing, and proofreading may be relevant.

Selection

We believe that a successful applicant should have a genuine interest in the development of mathematical models of physics. It will also be essential to actively take part in the experimental verification of the developed software and algorithms (optimization schemes). For this reason, the ability to work well in a group with other employees and students is necessary.

Mandatory qualifications:

• A master’s degree in Applied Physics, Engineering Mathematics, Engineering Physics or equivalent documented experience of numerical modelling with finite elements.
• Documented skills of advanced programming in e.g. MATLAB, Fortran, C/C++/C#, Python or equivalent language.

Other qualifications: experience of signal processing and measurement systems, ability to communicate orally and in written English, documented experience of research work and scientific writing (prior publications in the subject is regarded as a merit) and capability to communicate in Swedish is also regarded as a merit.

Duration and terms of employment:

Employment as a doctoral student shall be on an open-ended basis but not for longer than to a specific point in time and never for a period extending more than one year after receiving the doctoral degree. The initial appointment must not be for more than one year. The appointment may be renewed for no more than two years at a time. A person may be employed as a research student for a total of not more than eight years. The total period of employment, however, may not exceed the equivalent of four years of full-time study at the third level of higher education. (Higher Education Ordinance (SFS 1993:100) Chapter 5 section 7).

Applications are to be submitted electronically through the University West web-based recruitment tool, Varbi. Visit our website for more information.

The application must include:

• CV/Personal qualifications.
• Degree project of second level of higher education.
• Degree certificate of first and second level of higher education. Other documents which the applicant wishes to invoke.

Personal letter containing:

• Interest in the research topic.
• Previous experience regarding the proposed research topic and its research methods and scientific theories.
• Motive to pursue doctoral studies.

Approved written languages regarding papers, diplomas, grades and other relevant documents are Swedish and English, or translations into those languages. Attach the original when submitting translated documents.

If you would like to submit documents that cannot be sent digitally please contact HR-representative for further instructions.The application should reach University West no later than 2021-12-31

Wellcome with your application!