Numerical simulation for anti-shock characteristic of a marine gearbox system

The shock-resistant analysis method of a large marine gearbox system was studied. The equivalent static stresses under normal operation condition of the box and the gears were computed using statics and the nonlinear contact finite element method, the stress components were extracted from the result files of NX. Nastran. A coupled finite element model of box-bearing-shaft-gear was established. Then, the dynamic stresses generated by underwater explosion were computed using DDAM (dynamic design analysis method), the static and dynamic stress components of the corresponding elements were re-synthesized with Von-Mises criterion. The dimensionless residue coefficient of strength was introduced to assess the shock-resistant performance of the gearbox. To simulate underwater explosion environment, shock spectrum was matched to the form of assembled dumped sinusoids. The study results provided a theoretical basis for anti-shock performance assessment and shock isolation design of a marine gearbox.