Contributing towards the development of a ring tensile tests using FEM static structural calculations

SCK•CEN Mentor

Cautaerts Niels,, +32 (0)14 33 31 85

Expert group

Fuel Materials

SCK•CEN Co-mentor

Delville Rémi,, +32 (0)14 33 31 65



Nuclear fuel cladding material must be shown to maintain geometric and structural stability during operation of a reactor. Part of this effort is performing mechanical tests, such as tensile tests, to gauge how material properties evolve under different conditions. Cladding material however always has the geometry of a thin-walled tube. For this reason, it is difficult to manufacture representative tensile test specimens directly from the tubes. In addition, the manufacturing process makes the material highly textured, meaning that the properties in the axial and hoop direction could differ. Aggregate resistance to load of tubes is often tested by pressurized burst tests, but this requires specialized facilities, is difficult to implement in the hot cell for testing irradiated material.

To gauge properties of cladding tubes in the hoop direction, a ring-tensile test was developed at SCK•CEN and used extensively in the framework of another master thesis. This work will focus on interpretation, generalization and development of this test using FEM simulation.




The ring tensile test was developed specifically for a particular tube geometry in mind. The width of the ring was chosen ad hoc. Some basic modeling has been performed to interpret the results of this test geometry.

The objective of this work is to elevate this work to the next level. Different geometries, meaning tube diameter, tube thickness and ring width should be investigated. In addition, how the result is influenced by altering the mechanical properties, contact properties and numerical parameters should be mapped out. Some different geometries may be tested, such as a gauged ring design. The goal of the thesis is to validate a procedure to perform ring tensile tests and to analyze its results in order to extract meaningful mechanical properties. Work may also be extended to testing in different conditions (e.g. temperature with an integrated oven on the testing line) and environment (e.g. liquid metal Pb-Bi using a dedicated testing system).

Ideally, the candidate should have some knowledge in FEM modeling methods, particularly static structural calculations. ANSYS workbench is the preferred environment, but any experience is welcome. Some basic notions of materials science and mechanical properties, as well as some experience with programming in Python for data analysis would be a plus. Training will be provided for the use of material testing machines on which the student is expected to work independently.

The minimum diploma level of the candidate needs to be

Academic bachelor

The candidate needs to have a background in

Physics , Other