The recently revived Indian motorcycle company is changing from a custom builder to one capable of mass producing thousands of bikes, such as the Indian Chief 2002.

The complex frame for an Indian Chief is made of low-carbon steel tubing, castings, and forgings. Stress analyst Yuen used MSC.Nastran for Windows to see where it needed more material, thicker walls, and possibly a different gusseting design.

Engineers with an upstart motorcycle company turned to MSC.Nastran for Windows from MSC.Software, Santa Ana, Calif. (, to pinpoint trouble spots in a new motorcycle's structural members. "FEA played an important role in shaping the design of the Indian bike," says Derek Yuen, structural engineer with Indian Motorcycles, Gilroy, Calif. ( Yuen estimates the software let his team cut up to 25% off the design schedule. He says the FEA software also shortened the time to market by reducing the number of prototype failures and by streamlining their design process.

Conventional wisdom suggests making prototypes after completing analyses. Yuen prefers to complete analysis early in the design process. For the new Chief, however, time constraints made such a schedule impractical. Therefore, prototyping and analysis were done simultaneously. "We had prototypes made from preliminary drawings, and before the final design finished, we had a prototype up and running. In the end, FEA shaped our structural changes and helped correct problems that showed up onscreen or in a prototype part that broke after testing." Take the rear-seat structure, for example. FEA predicted unacceptably high stresses. A week later it broke. "We've had good correlation between FEA and physical prototypes," he says.

-- Paul Dvorak