- Literature review State-of-the-art residual stress measurement techniques Residual stress fields in rails, for both as manufactured and used rail Finite Element (FE) modelling of residual stresses
- Numerical modelling Modelling of a residual stress field in a rail Development of a framework to mimic the cutting of small specimen Develop a method to calculate the residual stress distribution in a full rail based on small specimen experimental results.
- Experimental research Residual stress measurements on a rail to validate FE model, using for example hole drilling Proposal for residual stress measurements on full rails. These experiments are not necessarily done within this graduation research.
- Follow a master in civil engineering, mechanical engineering, maritime engineering, architecture or the built environment.
- Have an affinity with steel structures
- Have an affinity with numerical modelling
- Have an investigative and critical attitude, you want to know why certain phenomena occur and determine its effect.
- Like to cooperate with others and are creative;
- Live in The Netherlands, and is willing to work at least one day a week at our office in Delft.
- Have excellent oral and written communication skills in English, and preferably Dutch.
Internship | Redistribution of residual stresses in small specimen - Delft, Nederland - TNO
Beschrijving
About this position
Fatigue is one of the decisive factors for maintenance of steel structures. Accurately describing the fatigue crack growth rate is crucial in determining the fatigue life. The fatigue crack growth rate is influenced by the residual stresses. Several techniques are available for the measurement of residual stresses such as the hole drilling method, X-ray diffraction, neutron diffraction and the crack compliance method. However often when preparing specimen for these measurements the structure needs to be cut in smaller pieces. Due to the self-balancing nature the residual stresses in a sample will redistribute. This leads to large uncertainty and the question when measuring the measured residual stresses on a small specimen does this still represent the real residual stresses in the whole structure. The focus of this project is on rails. Residual stresses in rails arise from manufacturing as well and redistribution during operation. An accurate description of the residual stress field throughout the whole cross section of the rail is therefore important.
What will be your role?
This graduation projects aims to identify the influence of the specimen size on the residual stress distribution, develop a method to predict the residual stress distribution in the full rail based on a small specimen residual stress measurements and if required propose an experimental method to overcome this problem. To reach this goal, the use of (advanced) numerical models, as for instance the finite element method (FEM), are foreseen, complemented with a validation measurement
The intended steps:
What we expect from you
This graduation position is offered to students that:
What you'll get in return
You want to work on the precursor of your career; a work placement gives you an opportunity to take a good look at your prospective future employer. TNO goes a step further. It's not just looking that interests us; you and your knowledge are essential to our innovation. That's why we attach a great deal of value to your personal and professional development. You will, of course, be properly supervised during your work placement and be given the scope for you to get the best out of yourself. Naturally, we provide suitable work placement compensation.