Engineering news
A new generation of indestructible bridges could be possible, according to researchers from the University of Warwick.
Form-finding enables the design of rigid structures that follow a strong natural form - structures that are sustained by a force of pure compression or tension, with no bending stresses, which are the main points of weakness in other structures.
This could, for the first time, lead to the design of bridges and buildings that can take any combination of permanent loading without generating complex stresses.
Such structures will have enhanced safety, and long durability, without the need for repair or restructuring.
The bridge design method, described in the latest issue of the journal Proceedings of the Royal Society part A, has been developed by the University of Warwick professor Wanda Lewis.
Lewis argues that bridges designed following her algorithm wouldn’t suffer from bending stresses and would therefore last much longer and require much less maintenance than those designed conventionally, mostly with aesthetics in mind.
“Aesthetics is an important aspect of any design, and we have been programmed to view some shapes, such as circular arches or spherical domes, as aesthetic,” said Lewis. “We often build them regardless of the fact that they generate complex stresses, and are, therefore, structurally inefficient."
The university discovered that fabric is suspended and allowed to relax into its natural, gravitational, minimum energy shape; then that shape is frozen into a rigid object and inverted. Lewis says the coordinates of this shape through computation by simulating the gravitational forces applied to the structure. This produces a shape (a natural form) that can withstand the load with ease.
While classical architectural designs are appealing to the eye, they aren't necessarily structurally sound, says Lewis. “Aesthetics is an important aspect of any design, and we have been programmed to view some shapes, such as circular arches or spherical domes as aesthetic. We often build them regardless of the fact that they generate complex stresses, and are, therefore, structurally inefficient.”