ABSTRACT
Corrugated iron is a thin sheet of either iron or steel that is folded, furrowed, ridged, waved, wrinkled, grooved, troughed, or curved. Corrugating of iron is the process of folding or fluting a flat metal sheet in order to increase its stiffness and, hence, its strength. Nature has many examples of forms designed to develop maximum strength with the minimum use of any given material. For example, an eggshell, because of its curved shape, is very strong, considering its thinness and brittle nature. Likewise, the curves and corrugations of seashells also have a high strength-to-weight ratio, as do the fibrous cellular structures of most plants and animals. Man has used the principle of corrugating for centuries, an early example being the manufacture of corrugated buckets in northern Italy from the seventh century BCE.1 The simple act of folding a sheet of paper to make a fan evidences of the universal application of the principle of corrugating that may indeed be as old as China’s invention of paper.
