The composite engine cover for the Speed 8 car is lightweight and can be shaped for the best aerodynamic properties.

Speed 8 from Team Bentley was designed for the 24-hr race of LeMans. During the race, speeds hit 210 mph and average over 135.

Engineers at Team Bentley know that if they can cut a car's weight to less than the 900-kg minimum for LeMans races, they will be able to add ballast where it will lower the car's center of gravity and improve handling. One way to remove weight is by building parts from composites. These materials, however, can distort if not laid up just right.

FiberSim software, from Vistagy Inc., Waltham, Mass.. ( takes distortion into account in predicting a part's final shape. It lets engineers judge the producibility of parts and generate manufacturing data for ply-cutting equipment.

The software simulates draping plies on 3D-digital models built in Pro/Engineer. For each parent ply, Graham Muff, composites manager at Racing Technology Norfolk in Norfolk, England, identifies qualities such as material type, thickness, and boundaries. Then Muff's team can test different manufacturing approaches. For example, they can change the point of initial lay-up in the mold, or split a ply into two or more. "On a complex surface like the engine cover, draped plies can distort so much that the material puckers or folds," says Muff. "The software helps us design for the minimum number of plies and optimum fiber orientations, so the cover has maximum strength."

-- Paul Dvorak