Rapoport–Samoilenko test for cathode carbon materials: I. Experimental results and constitutive modelling Original Research Article

The sodium expansion of semigraphitic commercial cathode material used for aluminium production has been measured on solid cylinder samples. Experimental results have been obtained for three current density values using the Rapoport–Samoilenko-type apparatus. A constitutive model for cathode carbon materials which is able to reproduce the relationship between the sodium expansion and time during the Rapoport–Samoilenko-type test has been proposed. Parameters required in the proposed model such as the sodium expansion after infinite time and the diffusion coefficient have been calculated from experimental data by a least-square minimization process. The distribution of sodium concentration, radial stress, tangential stress, axial stress, first principal stress and von Mises equivalent stress in the solid semigraphitic cylinder with time have been obtained.