Abstract
In this paper, a thermomechanical interaction of a ceramic breeder pebble bed and structural plate is studied based on a recently developed discrete numerical simulation code. The calculations take into account the coupling effect between structural wall deformation and pebble bed deformation, which greatly increases the computing time and complicates the computational procedures in determining the particle-wall contact characteristics. Specifically, the model is applied to a lithium orthosilicate packed bed for the evaluation of the deformation of a circular plate due to bed thermal expansion, while the results are compared with SCATOLA's experimental data. Numerical results using a fixed boundary condition show reasonable agreement with the experimental data. In addition, numerical simulations confirm an irreversible plate deformation after a thermal cycle run as observed in the experiments, although these experimentally observed deformations are larger than that of the numerical estimations. Moreover, numerical results of contact forces at contact points provide information concerning the mechanical integrity of the bed at a moderately high temperature.