Effects of Cracks on Anomalous Mechanical Behavior and Energy Dissipation of Negative‐Stiffness Plates

Abstract

Mechanical behavior of negative-stiffness (NS) plates containing cracks, under sinusoidal straining, are numerically studied with the phase-field modeling techniques. Ferroelastic phase transition is triggered by thermal loading with the Landau-type energy function to generate the double-well potential. NS arises from regions of the multi-domain plates, and interacts with surrounding positive-stiffness neighboring regions to give rise to anomalous mechanical behavior and energy dissipation. It is found that the anomalies in effective elastic modulus and damping are preserved in the presence of cracks, regardless of their shape or tip radius. Cracks do not diminish the negative-stiffness effects on overall properties; they may provide more enhancement in dissipation. Crack tips concentrate stress, and cause phase transition to start earlier than other regions in the plates. As opposed to passive materials whose overall damping must be positive, we observe negative effective damping in the plates due to generation of energy from the phase transition. Phase-Field Modeling of Negative-Stiffness Effects

Cancellation of Auxetic Properties in F.C.C. Hard Sphere Crystals by Hybrid Layer-Channel Nanoinclusions Filled by Hard Spheres of Another Diameter

“…Novel fabrics with auxetic properties [28,29,30,31], targeted for personal applications have been developed. Alongside the experimental studies, new theoretical models exhibiting negative Poisson's ratio [32,33,34,35,36,37,38,39,40,41,42,43,44,45,46] have been proposed. The search for the negative Poisson's ratio in known and naturally occurring materials revealed that around 70% of metals with cubic symmetry have such properties [47].…”

Poisson's Ratio of f.c.c. Hard‐Sphere Crystals with Cubic Supercells Containing Four Nanochannels Filled by Hard Spheres of Another Diameter

“…[19,20] In this work, we use the more recent classification [20] which distinguishes between nonauxetics, partial auxetics, and auxetics. Vast potential applications of auxetic materials drive the theoretical and experimental investigations, which branch into auxetic metamaterials, [21][22][23][24][25][26][27][28] models, [16,[29][30][31][32][33][34][35][36][37][38][39][40][41] structures, [42][43][44][45][46][47][48] polymers, [49,50] composites, [51] foams, [52][53][54] and fabrics. [55][56][57][58] Most of the research on auxetics is focused either on developing new materials or searching for auxetic properties in existing ones.…”

Enhanced Auxetic and Viscoelastic Properties of Filled Reentrant Honeycomb

“…[20] Using the phase field modeling, NS effects have been examined without directly assigning negative modulus values in calculations. [21,22] In addition, NS effects on the overall viscoelastic and coupled field properties have been investigated with the finite element analysis. [23] Furthermore, energy dissipation of a viscoelastic composite beam-column connector has been numerically analyzed to exhibit its high stiffness and high damping.…”

“…The inter‐relations between negative compressibility and NPR have been demonstrated that they are attainable . Using the phase field modeling, NS effects have been examined without directly assigning negative modulus values in calculations . In addition, NS effects on the overall viscoelastic and coupled field properties have been investigated with the finite element analysis .…”