Simulations of the thermomechanical contact between the fuel pellet and the shell inside a fuel rod using the Lagrange multiplier method with a detached contact boundary

P. V. Solomentseva


Abstract: The problem of contact interaction between fuel pellets and the shell inside a fuel rod is considered. The finite element method is chosen as the basic numerical approach, and a modified Lagrange multiplier method with a detached contact boundary is used to account for contact conditions. Calculations are performed for the interaction between the fuel pellet and the fuel rod shell under normal and emergency operating conditions. It is shown that in emergency operating conditions, mechanical contact occurs, leading to deformation of both the pellet and the cladding.

Keywords: contact problem, nite element method, Lagrange multiplier, detached boundary, fuel rode.