Nature's Way to Relieve Stress Inspires Designs for Nearly Indestructible BridgesNature's Way to Relieve Stress Inspires Designs for Nearly Indestructible Bridges

An engineer in the UK has found inspiration in nature for the design of bridges that are far stronger and more durable than current designs.

Emeritus Professor Wanda Lewis in the School of Engineering at the University of Warwick has been studying how nature relieves stress for 25 years, taking an approach called “form-finding,” a process of shaping an object, or a structure, by loads applied to it, she told Design News in an interview. This process is different than engineering methods that start from an assumed shape and then check the stresses and displacements in a structure under an applied load, she said.

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 without bending stresses, Lewis said. These stresses are the main points of weakness in structures and what causes bridges to fail or buckle under weight or stress and cause damage or even collapse.

“In form-finding, we go in the opposite direction -- the shape of the structure is not known initially, it is found by the application of load and involves repetitive calculations to find a shape that is in equilibrium with all forces,” she said.

An artist’s rending of the Rich Street Bridge in Ohio, an example of form finding to create more stable arches for bridge construction. Form finding is an approach taken by British engineer Wanda Lewis of the University of Warwick to observe how stress is balanced in nature and apply that to building stronger, more durable bridges. She said the Rich Street Bridge is a good example of how a form-found bridge might look.
(Source: Wanda Lewis/Department of Transportation, Ohio)