- SPECIAL REPORTS What if you could take the best materials
available, combine them anyway you need to, and produce the most
efficient, light-weight structures imaginable? What if you could
assemble those structures with adhesives? Welcome to the 21st
century. The development of fiber-reinforced composites is not
equal to that of smelting iron, but the advent of composites
significantly changed the scope of materials engineering. Wood,
the most common composite, required builders to design
structures based on the tensile and compressive properties of
unidirectional cellulosic fibers. Out-of-plane flexural
deficiencies were overcome by using more or thicker pieces,
albeit with a weight penalty. Composite structure allows for
directed fiber placement to tune load management because most of
the performance comes from the fibers. The resin matrix holds
the fibers together. Carbon-fiber reinforced composites have a
tensile modulus roughly equal to that of aluminum, but at only
60 percent of the weight. They have a