A paper on the mechanics of interlocking structures by a University of Hawaiʻi at Mānoa assistant professor highlights a discovery that could have far-reaching effects in the manufacturing and medical industries.
The paper, Nonlinear Mechanics of Interlocking Cantilevers, by Joseph J. Brown, assistant professor in mechanical engineering, was published in the Journal of Applied Mechanics. The research explored the mechanical behavior and design of simple interlocking structures and was conducted in collaboration with colleagues from the University of Colorado.
Mechanical interlocking is the behavior that occurs when parts are assembled by sliding them together until they “snap-through” into a final position. Until now only a few types of interlocking joints could be modeled, but this paper expands the ability of engineers to design and analyze snap-together systems.
The team started exploring this problem after earlier work in nanotechnology fabrication led to its demonstration of surfaces that joined together by ultrasmall (less than 300 atoms thick) interlocking tabs.
In the new paper, the team compared mathematical and computational models of a simple snap-together system and tested these models with an experiment. The results of this work demonstrated snap-through results from the geometry of a problem and that these systems can be designed to achieve at least a 50-times difference between the force required to press them together versus the force required to pull them apart.
The team projects that, in addition to providing a basis for further work in large-deflection mechanics (the study of objects subject to a large amount of bending), the discovery will contribute to design of new part assembly mechanisms for manufacturing and medical materials.
Some possible applications include ultrahigh temperature joints, medical adhesives, joining of dissimilar materials and assembly of complex or flexible parts.
Brown joined the Department of Mechanical Engineering in August 2017. Prior to coming to UH Mānoa, he was a senior research associate at the University of Colorado Boulder.