Search arXiv⌕ Search

arXiv · 2610.39836

A guide to enriched continuum modeling: advances on wave propagation in metamaterials through the relaxed micromorphic framework

Abstract

This contribution provides a systematic framework for modeling the dispersive behavior of mechanical metamaterials by an enriched continua approach using the relaxed micromorphic model (RMM). We give the identification of its frequency-independent constitutive parameters from Bloch-Floquet dispersion data of the periodic metamaterial by combining analytical relations for characteristic features with a subsequent numerical optimization. Particular emphasis is placed on the underlying structure and limitations of the resulting dispersion relations, including their cut-offs, and asymptotic behavior. Finally, the transition from infinite periodic media to finite-size specimens is addressed, highlighting the role of the microscopic unit-cell cut and discussing null-Lagrangian contributions, effective interface forces, and surface Lagrangians as approaches to incorporate boundary effects.

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Jendrik Voss, Svenja Hermann, Mohammad Sarhil, Patrizio Neff, Angela Madeo. 2026-10-29. A guide to enriched continuum modeling: advances on wave propagation in metamaterials through the relaxed micromorphic framework. https://arxiv.org/abs/2610.39836

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related papers

Strain Functionals: A Complete and Symmetry-adapted Set of Descriptors to Characterize Atomistic Configurations

Extracting relevant information from atomistic simulations relies on a complete and accurate characterization of atomistic configurations. We present a framework for characterizing atomistic configurations in terms of a complete and symmetry-adapted basis, referred to as strain functionals. In this approach a Gaussian kernel is used to map discrete atomic quantities, such as number density, velocities, and forces, to continuous fields. The local atomic configurations are then characterized using nth order central moments of the local number density. The initial Cartesian moments are recast unitarily into a Solid Harmonic Polynomial basis using SO(3) decompositions. Rotationally invariant metrics, referred to as Strain Functional Descriptors (SFDs), are constructed from the terms in the SO(3) decomposition using Clebsch-Gordan coupling. A key distinction compared to related methods is that a minimal but complete set of descriptors is identified. These descriptors characterize the local geometries numerically in terms of shape, density, and orientation descriptors that recognize n-fold symmetry axes and net shapes such as trigonal, cubic, hexagonal, etc. They can easily distinguish between most different crystal symmetries using n = 4, identify defects (such as dislocations and stacking faults), measure local deformation, and can be used in conjunction with machine learning techniques for in situ analysis of finite temperature atomistic simulation data and quantification of defect dynamics.

physics.app-ph↗

Hyperbolic dynamic friction models for viscoelastic sliding and rolling contact

This paper considers the sliding and rolling contact between viscoelastic bodies. Combining linear viscoelastic rheologies for bristle-like elements with nonlinear dynamic friction models, and under the assumption of small deformations and displacement gradients, it derives a class of viscoelasto-kinematic equations, formulated as a system of semilinear partial differential equations (PDEs) governing the evolution of the frictional force, bristle deformations, and internal state variables at the interface between the contacting bodies. The resulting system is analysed mathematically, demonstrating that linear viscoelasticity preserves the hyperbolic character of the PDE systems typically encountered in rolling contact. The proposed theory is illustrated through representative examples of both sliding and rolling contact, highlighting that these two processes, whilst often treated as distinct, may in fact exhibit closely related underlying dynamics. Overall, the framework provides a general theoretical setting applicable to a broad class of viscoelastic frictional systems.

physics.app-ph↗

Design, Modeling, and Validation of Curvature-Based Shape-Aware Flexible Phased Arrays

In situ knowledge of array geometry enables mechanically flexible phased arrays to recover beam-steering performance under deformation without receiver-side RF feedback. This work presents a comprehensive engineering study of curvature-based shape sensing, combining numerical sampling-density and measurement-noise analysis, physical modeling of sensor response, and experimental shape and RF characterization. A study of 11,000 Bézier curves quantifies reconstruction error versus curvature-sampling density and noise, guiding the selection of nine sensing locations. A physical model relates PCB curvature to strain-gauge output voltage, with predictions compared against calibrated sensor measurements. The sensing system is integrated with an eight-element, 6-GHz flexible array and a low-cost, size-scalable, digitally controlled eight-channel phase-shifting module providing 360° tuning with better than 7-bit effective resolution. Across 12 fixture-conformed shapes, including five previously reported cases, the average reconstruction error is 0.06$λ$. Three additional air-suspended configurations, not prescribed by analytical curves, show an average positional difference of 0.095$λ$ between curvature-based and image-based estimates. Measured radiation patterns demonstrate broadside correction and steering to $\pm$30°. These results provide quantitative engineering guidance for designing and characterizing curvature-based shape-aware flexible phased arrays.

physics.app-ph↗