Stiffness and damping are conflicting requirements in many material systems. High stiffness is required in a wide range of structural components to provide sufficient robustness under demanding loading conditions. Simultaneously, a structure should be able to effectively mitigate shock and vibrations dynamically transmitted to it by the environment. However, today’s structures typically exhibit limited adaptability and damping capabilities. The Structural Logic project aims at developing a library of high-performance structural components that can simultaneously provide high stiffness and high damping capabilities. This is achieved through a broad perspective to structural design, which integrates several concepts into structured configurations featuring multiple materials arranged in optimized topologies. Since stiffness and damping refer to structural response in two different regimes, i.e. static and dynamic loading conditions, respectively, the basic idea is to combine a backbone structure suitable to meet stiffness requirements with metamaterial inclusions designed to provide the desired shock and vibration control. The design approach exploits the following concepts. Internal resonators are used to pump energy away from the structure at desired (typically low) frequencies. Peculiar resonator geometries are investigated to achieve normally unattainable loss-stiffness performance through inertial amplification and/or unusual material properties such as negative Poisson’s ratio. Viscoelastic damping is exploited to dissipate the energy captured by the resonating systems. Periodic and graded arrangements of resonating and viscoelastic units are considered in order to impede the propagation of elastic waves within the structure, thus preventing the onset of vibrations. Current implementations of the outlined concepts include uniform and graded lattices of inertially amplified internal resonator (IAIR) elements as well as unit cells with chiral topologies.
Georgia Institute of Technology – School of Aerospace Engineering Atlanta, Georgia 30332-0150 Contact Us:
Massimo Ruzzane Emanuele Baravelli	ruzzene@gatech.edu ebaravelli@gatech.edu
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