Farmington Hills, MI -For years, the auto industry's choice for side-impact crash analysis has been SID-the Side-Impact crash Dummy.
Now, automotive engineers are moving toward a different technique: using servers to simulate the complex interactions of a side impact. Engineers at Automotive Systems Lab-oratory (ASL) employ a Hewlett-Packard V-Class server to develop better crash-restraint systems. The servers have helped them better understand the effect of side crashes on automotive structures, as well as on humans. They are currently studying, for example, what happens when an occupant's head hits the door trim.
Unlike frontal crashes, side impacts have not always fallen within the realm of computer simulation. The reason: Side impacts are far more complex and, therefore, more computation-intensive using finite element analysis. "A frontal crash typically has several thousand elements," notes Wenyu Lian, engineering manager for airbag research and development at ASL. "But a side impact FEA model can have up to one million elements." For side impact analysis, the firm uses PAM-CRASH, a finite element analysis program from the ESI Group of France, and Dytran from MSC.Software for analysis of airbag performance.
Engineers say they could have used supercomputers to perform such simulations. But those often cost in excess of $10 million. Computer workstations costing $10,000 lacked the speed for such computation-intensive operations.
Servers fall somewhere between those two extremes. Hewlett-Packard's V-Class servers, for example, cost between $200,000 and $1 million each. The V2250, which ASL used, is based on the fundamental design principles of a vector supercomputer, but employs a scalable architecture. It incorporates four 240 MHz processors and has 4 Gbytes of memory. Theoretical peak performance with four processors is 3.8 GigaFLOPS.
Engineers say that the V-Class offers a level of performance that can't be obtained with a workstation. In the side-impact application, for example, it provided solutions five to ten times faster than a workstation could have. "Supercomputers offer a higher level of performance than servers, but the prices are off the charts," notes Knute Christensen, mechanical engineering market development manager for Hewlett-Packard's Technical Computing Division. "But a server can take an application like this one and open up a whole new set of possibilities."