Showing papers in "Extreme Mechanics Letters in 2020"

TL;DR: In this article, the authors investigated the performance of 11 common household fabrics at blocking large, high-velocity droplets, using a commercial medical mask as a benchmark, and found that most fabrics have substantial blocking efficiency (median values >70%).

TL;DR: In this paper, a review of the recent advances in the theory of dielectric elastomer and demonstrates some examples of using theory to design DE transducers is presented, from the simplest homogeneous deformation of a flat membrane to the highly complex bifurcations of a tube.

TL;DR: In this paper, a novel family of mechanical metamaterials that are simply composed of n + 1 sets of planar plates layered in a transversely quasiperiodic manner was designed.

TL;DR: In this article, a novel architected lattice metamaterial with broadband and multiband bandgap characteristics is studied, where a slight structural modification in a regular lattice structure has succeeded to significantly magnify the vibration attenuation capability of these lightweight periodic lattices.

TL;DR: In this paper, the influence of structural porosity and shell thickness on the compressive response of a P-TPMS lattice structure has been separately studied and an enhanced design method, based on local shell thickening, is proposed to obtain a lightweight structure with superior mechanical properties.

TL;DR: In this article, the deformation induced geometry and material nonlinearities of the elastomeric matrix and coating are intentionally exploited to tune the dynamic responses of acoustic metamaterials.

TL;DR: In this article, a pneumatically actuated tunable negative stiffness mechanical metamaterial with real-time tunable properties is presented, which enables a wide range of mechanical properties but is hard to design and fabricate due to its complexity.

TL;DR: In this paper, the authors carried out experiments on polyacrylamide (PAAm) gel and discovered scaling-laws that differ significantly in the swollen and dehydrated state in addition to contradicting the Flory-Rehner theory.

TL;DR: In this paper, the silver nanowires (Ag-NWs) were employed combining with polylactic acid (PLA) to create a novel electrically driven 4D printing composite.

TL;DR: A new approach to design and optimize curved beams based on machine learning, which has been successful in many fields owing to its ability to process big data that can also be used in structural design and optimization, is demonstrated.

TL;DR: It is illustrated how data-driven modeling can integrate classical epidemiology modeling and machine learning to infer critical disease parameters—in real time—from reported case data to make informed predictions and guide political decision making.

TL;DR: In this paper, a dual scale hybrid mechanical metamaterial consisting of simple cubic structure, body-centered cubic structure (BCC), face centered cubic structure unit cells at different scale levels were designed and proposed for impact energy absorption, where one large type A unit cell and eight (2 × 2 × 2) small periodicspatially architected type B unit cells with half size of type A cell along X, Y and Z directions were integrated together for harvesting final hybrid metammaterials.

TL;DR: In this article, the effect of interlock on the tensile and fracture performance of nacre-like composites is investigated. But the authors focus on the tablet waviness angle instead of the aspect ratio of the stiff phase.

TL;DR: In this article, the authors proposed a two-dimensional elastic anisotropy index (A SU ) which is shown to be applicable for all 2D crystals and derived the specific forms of their 2D counterparts.

TL;DR: In this article, the robustness of topologically protected edge states with zigzag, bridge and armchair interfaces in a new twisted phononic plate was investigated and a map of robustness as a function of both frequency and twisted angle was presented.

TL;DR: The hyperbolic unit cell of flying beetles is inspired by the double-layered morphology of the forewing shells of flying beetle shells as discussed by the authors, and the tessellation schemes that populate the microstructure to a component level are stirred up by the similarity with Euclidean tiling of convex regular polygons.

TL;DR: A rotational speed sensor is of great importance for the development of modern industrial automation and reliability, integration, measuring range and accuracy are key characteristics to its application as discussed by the authors, which can be improved significantly by modifying the bearing's structural characteristics.

TL;DR: The method starts from selection of the structural bases based on the existing studies and then combines performance evaluation together with structural evolution to construct meta-atoms with specified properties to design metamaterials.

TL;DR: In this paper, a 3D compression-torsion cubic mechanical metamaterial (CTCMM) with double inclined rods is proposed to convert axial compression into a torsion.

TL;DR: In this paper, a type of multi-stable metastructures exhibiting both level and tilted stable configurations is proposed based on 2D and 3D arrangements of bi-stable elements.

TL;DR: In this article, a combination of J-integral failure criterion and the equivalent material concept (EMC) was implemented to investigate failure of U-notched 3D-printed parts.

TL;DR: A benchmark data set for constructing metamodels of heterogeneous material undergoing large deformation is introduced (Mechanical MNIST) and it is anticipated that it will enable the broader community of researchers to develop improved meetamodeling techniques for mechanical data that will surpass the baseline performance that is shown here.

TL;DR: This work adopts variational autoencoder (VAE), a machine learning generative model to learn a latent, reduced representation of a given RVE configuration that allows to perform Bayesian optimization (BayesOpt), a sequential optimization strategy, for the multi-material design problems.

TL;DR: This work reveals the potential of a novel paradigm to design architected materials via semi-supervised learning, and inspires applications such as using sparse sensors in truss designs in additive manufacturing, architectures and civil infrastructure under complex loading conditions.

TL;DR: In this article, the authors show that for a solution of thickness of 50 microns adhesion energy of 50 Jm−2 is attained in 60 s. They illustrate this concept using two pieces of polyacrylamide hydrogels as adherends, an aqueous solution of cellulose as stitch polymers, and a change in the pH in the cellulose solution as a trigger.

TL;DR: In this article, a laser-based Inertial Microcavitation Rheometry (IMR) technique was used to study the deformation constitutive behavior of soft materials at ultra-high strain-rates.

TL;DR: By imagining the mechanical design as a "game" to make clear what is the “score” to maximize, reinforcement learning is successfully applied to the design of layered phononic crystals with anticipated band structures, which can regulate elastic waves by blocking the waves in the range of bandgap.

TL;DR: In this article, two novel chiral block lattice topologies are conceived having interesting auxetic and acoustic behavior, which are made up of a periodic repetition of square or hexagonal rigid and heavy blocks connected by linear elastic interfaces, whose chirality results from an equal rotation of the blocks with respect to the line connecting their centroids.

TL;DR: In this article, the authors analyzed the mechanical properties of a typical multistable mechanical metamaterial and found that the largest peak force and best energy absorption efficiency can be obtained by adjusting its geometrical parameters.