The job of structural engineers around the world is arguably getting more difficult. Many urban centers are experiencing booming populations and increased vehicle traffic, and environmental changes create new challenges for buildings, bridges, and roadways. New breakthroughs in engineering design from the University of Warwick could lead to indestructible bridges that rely on compression for their strength, and lack the weak points that make traditional bridges so vulnerable. And the design process is inspired by nature.
Wanda Lewis of University of Warwick’s School of Engineering employs the process of ‘form-finding’ to create bridge designs that need little or no maintenance or repairs. For a quarter century, Lewis has been studying forms in nature to learn how simple stress patterns make it possible for delicate objects, such as a leaf on a tree, to withstand the intense force of wind, rain, or impact against a tree branch. Although she says “nature’s design principles cannot be matched by conventional engineering design,” she has developed a mathematical model that could lead to super durable manmade bridges.
The optimal arch—a fully self-supporting bridge structure—has been the target of engineers for centuries, and Lewis’ research could be the key that unlocks the next wave of structural engineering. Her mathematical models respond to the failings of the inverted parabola and the catenary form, classical theory’s only two existing concepts for an optimal arch which both have weak points. The new models could help engineers build bridges that can withstand not only heavy regular traffic, but also earthquakes, floods, and high winds.
Her findings were recently published in the journal Proceedings of the Royal Society A: Mathematical, Physical and Engineering Science.