Doctoral student's system reduces steel needed for heavy structures

Michael Bunch

Michael Bunch

A new structural system with the potential to significantly reduce the amount of steel required to construct bridges, arches, domes and columns is being developed with cues from nature by Michael Bunch, a Ph.D. architecture student at Texas A&M.

By combining “golden mean ratios,” a standard proportion for width’s relation to height used in architecture and art for centuries, the radius of rotation around the centerline of DNA molecules, and the dimensions of a mathematical curve called a Koch Star, Bunch created test columns made with 3/8’ – inch rebar 54” tall with a 12” triangular base.

“Golden mean ratios occur repeatedly in design and in nature, DNA’s rotation radius has been around for millions of years, and the Koch Star appears in many types of analysis of natural and manmade objects,” said Bunch.

He built the test columns at the College of Architecture’s Digital Fabrication Facility, aka the Architecture Ranch, tested them with a hydraulic compressive testing machine in the Department of Civil Engineering’s structural lab, was unhappy with the results, refined the design, tested them again and found the columns were much stronger.

“I am continuing to evolve the design and will test two more steel models later this semester,” said Bunch, who has received a patent for his idea.

Bunch’s use of patterns in nature to inform his work is called biomimicry, an innovation method that seeks sustainable solutions by emulating nature’s time-tested patterns and strategies.

“We have a great deal to learn from nature,” said Bunch. “Nature rarely wastes anything. If it doesn’t work in the most efficient manner it ceases to exist.”

Bunch said the system could be manufactured from tubes of high-density nanoparticles or carbon fiber using 3-D printers, or built with conventional materials on computer-aided bending, welding and CNC equipment.

posted September 28, 2012