Application of contact mechanics for fretting damage of fuel rod: part 2 contact stresses under sequential shear

For the analysis of the fretting problem of the fuel rods, present paper(Part 2) shows the contact stresses on the contact surfaces between the fuel rods and the spacer grids. The influence functions and the numerical method presented in the Part I were utilized. For the shear load path, increase in transverse increase in axial decrease in transverse decrease in axial increase in transverse increase in axial direction was considered for simulating the rod vibration in a reactor core. After the Mindlin-Cattaneo solution was obtained for the transverse direction, the increase of axial shear load was considered at first. Compliance change, the behaviour of the stick/slip region and the surface displacement were investigated as the shear load followed the closed path. When cyclic closed load path was incorporated, the steady state of the contact stresses was achieved. A fretting failure parameter was discussed with the concept of energy release