The markets: Utility infrastructure (2011)
As natural insulators with high dielectric strength, fiberglass composites revolutionized the handling of electricity when they first replaced wood and metal in 1959. Today, they're also replacing steel cores in high-voltage transmission lines and helping to regulate power flow on the electric grid.
Utilities in the U.S. and elsewhere are working with composite suppliers to take advantage of fiberglass for power transmission towers, distribution poles and cross-arms as well as the aluminum conductor cables they support. Pultruded and filament wound composite utility poles and cross-arms are overcoming buyer resistance as electric power companies employ them primarily as replacements for aging wood poles in remote and/or extremely humid locations. In composite-reinforced aluminum conductor (CRAC) cables, the traditional steel strength members are replaced with a pultruded continuous-fiber core, which is expected to reduce weight and increase power-transmission efficiency by 200 percent. Because CRAC cabling weighs less than steel-cored cable, it is expected to be an attractive alternative for upgrading power lines: An increased number of cables can be hung from each existing tower, increasing power transmission capability without the huge expense of erecting new towers or obtaining additional rights-of-way.
The structural properties of composite materials are derived primarily from the fiber reinforcement. Fiber types, their manufacture, their uses and the end-market applications in which they find most use are described.
Fiber-reinforced plastic (FRP) replacing coated steel in more reinforced-concrete applications.
The matrix binds the fiber reinforcement, gives the composite component its shape and determines its surface quality. A composite matrix may be a polymer, ceramic, metal or carbon. Here’s a guide to selection.