By David Murgado
New challenges and advances in technology call for special types of materials. Materials that show extreme properties make them excellent candidates to solve problems where ordinary materials cannot perform. In this field of extreme materials, a variety of properties can be sought such as extreme deformations and amazing mechanical properties. From stretchable electronics to cable deployments in the ocean, flexible actuators to vibration absorbers, the research of Dr. Davide Bigoni has focused on applying these types of materials to real-world applications.
Bigoni, Professor of Solid and Structural Materials in the Department of Civil, Environmental & Mechanical Engineering at the University of Trento in Italy, spoke in the Mechanics Seminar at the University of Wisconsin-Madison in November 2018. Bigoni is also the head of the laboratory for Numerical Modelling of Materials in the University of Trento which has developed new boundary element and finite element modelling techniques for linear and nonlinear materials. His research group focuses on the investigation of the behavior of materials and structures subject to a variety of different loading situations.
An important topic discussed by Bigoni is that of folding and faulting. Folding – from a simple piece of paper to layers of rock in the Earth’s crust – is an extremely localized bending process that can only be explained within the constrained Cosserat elasticity. In his work he proves that the mechanism of folding works like the formation of shear bands in a plastic material. This approach is derived from a new two-dimensional Green’s function for applied concentrated force and moment and for example can explain geological formations like the Chevron folding that can be found in certain layered rocks.
Another of Bigoni’s innovations comes from his study of follower loads, where a load pushes at the end of a rod. Where many other researchers had failed in the past, Bigoni was able to succeed. He showed the academic world a new way of explaining and modeling follower loads. In certain cases, these loads can provide energy to their system creating periodic self-oscillating modes or flutter. He successfully created an apparatus using viscoelastic rods that determined the onset of flutter instability and the onset of divergence at a higher load. These studies have opened new avenues for structural analysis and design.
Bigoni’s work has opened a new world of possibilities in the field of structural analysis where the science of extreme materials will give shape to the applications of the future.