Altair > Case Studies > Improving Rudder Shock Loading Following a Nearby Blast Event Using RADIOSS

Improving Rudder Shock Loading Following a Nearby Blast Event Using RADIOSS

Technology Category

Application Infrastructure & Middleware - Event-Driven Application
Sensors - Gyroscopes

Applicable Industries

Buildings
Marine & Shipping

Applicable Functions

Product Research & Development
Quality Assurance

Use Cases

Structural Health Monitoring
Tamper Detection

Services

Testing & Certification

About The Customer

Assystem is a company with 50 years of experience and has become a key partner of the world's largest industrial groups including Airbus, Areva, Alstom, EDF, EADS, General Electric, MTU, Peugeot, Renault, Rolls-Royce, Safran, Thales and more. They are involved in designing and developing the products and services of tomorrow, building and ensuring the optimum use of their investments throughout the life cycle, coordinating and executing the realisation of their projects and infrastructure. Assystem's engineering teams make the difference and instil trust.

The Challenge

The challenge was to assess the capability of a ship's rudder assembly to withstand the shock loading following a nearby blast event. This was a critical task as the engineers in the Marine, Shipbuilding, and Offshore industries face many design challenges including physical space constraints, extreme weather conditions, deep water and remote locations. These constraints create an extreme environment for the engineer to develop a sound, reliable and safe operating platform. Prior to the installation of a modified design of a ship's steering gear, it was required to assess the capability of the rudder assembly to withstand the shock loading following a nearby blast event.

The Solution

To solve this problem, Assystem conducted dynamic explicit analysis using elastic-plastic material models. The mesh was produced using Altair's high performance finite element pre-processor HyperMesh, the analysis was conducted in leading structural solver RADIOSS, and the results were reviewed using post-processing tool HyperView. Multiple loading scenarios were solved to ensure that the limiting behaviour was captured. The model was verified using a combination of test cases compared to empirical solutions, by review of the in-built quality checks, and through monitoring output. In addition to strength checks, sectional forces and seal displacements were assessed. Design improvements have been implemented, based on the results of the analysis. The rudder carrier legs were strengthened to improve the bending resistance.

Operational Impact

The operational results of the solution were significant. The initial design of the rudder carrier showed excessive plasticity in the lower legs produced by a bending moment resulting from impact between the rudderstock and carrier. The rudder carrier legs were therefore strengthened by connecting to the seal carrier to improve the bending resistance. The sectional properties were also increased at the shoulders. This improvement in the design of the rudder carrier legs not only enhanced the strength of the rudder assembly but also increased its ability to withstand shock loading following a nearby blast event. The use of simulation technologies to improve design efficiency and reduce physical testing costs continues to become one of the best ways to address engineering challenges in the marine industry.

Quantitative Benefit