AbstractAnalysis of the thermomechanical interactions of fusion blanket materials and physical elements, particularly those involving particle bed design concepts, have been performed. The results show that the stress caused by the high thermal expansion of the blanket particle bed material is not excessive enough to be of concern for the structural material. However, its magnitude could lead to ceramic particle breakage if the bed behaves like a solid material. Furthermore, the calculations show that the clad deflection caused by this stress could lead to a possible separation between the bed and clad, which would add an unfavorable thermal resistance to the region and increase local temperature. A comparison between the estimated stress extrapolated from the experimental data and the analytical results shows that the thermomechanical performance of the pebble bed approaches that of solid materials.