Case Study: Assystem strengthens rudder to withstand blast-induced shock with Altair RADIOSS

Improving Rudder Shock Loading Following a Nearby Blast Event Using RADIOSS

Assystem, a 50‑year engineering firm serving major industrial clients, needed to assess whether a ship’s rudder assembly could survive shock loading from a nearby blast event. They engaged Altair and used the HyperWorks suite—employing HyperMesh for meshing, RADIOSS for dynamic explicit analysis, and HyperView for post‑processing—to model elastic‑plastic behavior and multiple blast loading scenarios on the steering gear and adjacent ship structure.

Altair implemented verified RADIOSS simulations run on parallel clusters to evaluate plastic strain, section forces, seal movement and velocity response under varied load directions. The analysis revealed excessive plasticity in the rudder carrier legs; design changes (strengthening the carrier legs and increasing sectional properties at the shoulders) were implemented, improving bending resistance, reducing plastic deformation and seal displacement, and ensuring the rudder met performance requirements.

Assystem

David Hunt

Principal Stress Engineer