A manufacturer had contacted us to perform a structural analysis of an “S” type ladle turret rotating arm and support structure. The objectives of the analysis were to determine the general state of stress within the arm especially at the welded joints and to determine its deformation behavior.
The analysis results showed that, the displacements of the arm proper are within acceptable limits and that the arm will develop relatively low stress levels due to the conservative design loading conditions imposed (1.5 dynamic load factor). Two of the loading conditions, a loaded ladle horizontally bumping the locating stops (LC2) and the inertial resistance of a loaded ladle to arm motion (LC3) produced stresses of less than 5 ksi.
The support frame developed stresses of up to 20 ksi in the vertical gusset plates and the web when subjected to a vertical load due to a fully loaded ladle in one bay and nothing in the other bay (LCIB). This loading is the most critical condition. Replacing the gussets with larger ones reduced the stresses in the gussets to less than 12 ksi. The stresses in the web were reduced to 18 ksi.