CASE REPORT  

Faster, more accurate crash simulation

• Increase productivity by reducing the crash simulation phase of development

The solution:

• High performance workstations, server supercomputer, graphics computer and two servers from SGI.

The result:

• Potential savings of £2.5 million because one phase of physical testing has been removed.

• Models now include 250,000 elements compared with 70,000, giving greater detail on the components expected to fail in a crash.

• Overnight turnaround on complex analyses.

• Length and cost of overall design process reduced because analysts can predict safety performance with greater accuracy.

The customer:

‘3D visualisation is critically important to us. It is likely to become more important as we change the way we transmit information to the user. We plan to develop a server-based web environment that will allow anybody to pull up the crash results for a particular vehicle and to visualise those results."

John Hemmings, Senior Manager Crash Simulation, Rover

back to top

Rover Group is Britain’s largest motor manufacturer. A subsidiary of BMW, it produces over half a million vehicles a year. With annual sales of £6,475 million it employs 39,000 people across the world.

Global competition places many demands on vehicle manufacturers and one of these is rising quality and safety standards. Vehicle performance under crash conditions is controlled by legal requirements but until 1992 results were confidential to manufacturers. Since then, when German automotive magazines began to conduct their own crash tests and publish results, the wide availability of this information has made safety performance a key issue in purchasing decisions.

The use of digital prototypes is critical to reducing the cost and length of crash testing - a physical prototype can cost as much as £250,000 and can take over 4 months - for a crash test lasting 0.1 seconds. Digital testing also enables changes to be made early in the design process. As John Hemmings, senior manager of crash simulation at Rover says, "Getting design right at an early stage is essential." He estimates that once manufacturers have been given specifications for production tooling of a prototype, the cost of a design change can be over £200,000.

Digital testing also ensures quality. If safety features are not an integral part of the car’s design from the start, their inclusion will add weight to the vehicle. This can have an impact on noise and vibration levels and can increase fuel consumption and emissions. Rover therefore relies heavily on simulated crash tests which need to be as realistic as possible.

Prior to 1996, Rover’s crash analysis team conducted its research using a Cray YMP supercomputer at British Aerospace. This resource was shared with other analysis groups at Rover. According to John Hemmings "Competition between analysis groups for time on the supercomputer was great and the crash analysis department was often unable to access the system."

The situation was made worse by the complexity of using the system which required various stages of data conversion and the use of an FTP network. It could take several hours to receive data back from the Cray. As a result it was taking up to 4 days to turn a job around.

In 1996 a redesign issue which put the whole process to the test prompted a full review of Rover’shareware, software and modelling systems.

A SGI system was being used to perform complex crash analysis tests at BMW’s Munich design centre and Rover’s parent company confirmed the system’s reliability and technical performance. BMW also recommended SGI for its excellent relationships with suppliers of visualisation software. In addition Rover had confidence in SGI’s future, John Hemmings explains "Silicon Graphics was also able to show us a five to ten year roadmap for its hardware."

In 1996 Rover updated its workstations to include two O² workstations, six INDIGO workstations and 17 OCTANE workstations. It also implemented one dedicated POWER CHALLENGE XL server plus two Onyx graphics supercomputers. Rover later added an Origin 2000 CC NUMA server plus an Origin 200 Filer Server.

The two O² s and 17 OCTANE workstations can be used to drive portable projectors for presentations off site. The dedicated server means that Rover obtains overnight turnaround. At the same time Rover upgraded its software. This has reduced time spent on data translation.

The upgrade of hardware, software and modelling facilities has allowed analysts to predict safety performance with greater accuracy and this has helped Rover reduce the length and cost of the design process. One particular phase of physical testing has been completely removed. As this previously accounted for up to ten prototype cars, at £250,000 each, the potential saving is £2.5 million.

SGI hardware has enabled Rover to move from 70,000 element models to 250,000 element models. These allow the crash analysis team to model the entire structure of a vehicle and its passengers whereas they could previously only simulate individual parts.

In addition to these improvements collaboration between teams is enhanced through Rover’s 3D visualisation centre. This has a 20’ wide x 8’ high screen with a dual projection system which displays car designs in full size. It enables designers and engineers to view and discuss crash data.

As John Hemmings says, ‘3D visualisation is critically important to us. It is likely to become more important as we change the way we transmit information to the user. We plan to develop a server-based web environment that will allow anybody to pull up the crash results for a particular vehicle and to visualise those results."

Copyright © SGI 1999