A 3D pantographic metamaterial behaving as a mechanical shield: Experimental and numerical evidence
The article “A 3D pantographic metamaterial behaving as a mechanical shield: Experimental and numerical evidence” is now published in the journal Materials
& Design.
The paper, co-authored by Alessandro
Ciallella, Ivan Giorgio, Emilio Barchiesi, Gianluca Alaimo, Alberto Cattenone,
Benjamin Smaniotto, Antoine Vintache, Francesco D’Annibale, Francesco dell’Isola,
François Hild and Ferdinando Auricchio, reports the results of experiments on
multilayer pantographic metamaterials, i.e., pantographic blocks, which
showed peculiar mechanical behavior.
The pantographic block, which is the subject of the present paper, has been printed using a Powder Bed Fusion technology and its hinges may be modeled as perfect ones. In the reported in situ 3-point flexural test, the predictions obtained by second gradient models for its mechanical response are shown to be experimentally consistent thanks to measurements via Digital Volume Correlation. The strain applied by the upper central support is almost entirely shielded by the pantographic block, i.e., the specimen barely crosses the lower reference plane defined by the lower lateral supports, even when subjected to very high stresses. The mathematical model employed here captures this observation in terms of a nonlinear “arching” effect activated in the beams of the pantographic structure, provided that elastic locking is introduced to prevent zero-energy modes of the pantographic structure.