High-strain rate deformation caused by microparticles impacting at high velocities is used to refine the microstructure of metallic materials to the nanocrystalline regime. Under these conditions, metallic targets and particles show a gradient distribution of nanograins, with size increasing away from the impact surface. Some of the mechanisms responsible for the refinement process are still not fully

This paper discusses the problem of macroscopic modeling a knitted technical fabric with the aim to determine a constitutive law for adequately modeling the material response under real-life load. As phenomenological, hyperelastic material laws reveal different parameters due to different test modalities used to identify such parameters, an optimization scheme is proposed to determine an objective

A weak interface model with a predefined traction-separation relationship (denoted as the cohesive zone law), when embedded in a bulk solid, is oftentimes adopted to simulate the crack advancement and thus determine the crack resistance under either monotonic or cyclic loading conditions. To-date, various types of loading-unloading irreversibility and hysteresis are only presumed in the cohesive zone

Pores in granular materials may occupy significant material volume. Pore-scale dynamics, therefore, strongly influence the macroscopic response of these materials when they are subjected to rapid compaction. In Part I of this series, Ghosh et al. (2024) employed in-situ X-ray imaging coupled with mesoscale finite element modeling to reconstruct the 3D time-resolved kinematics and kinetics of aluminum

In this work, a NiTi shape memory alloy (SMA) with excellent elastocaloric performance (with an ultrahigh coefficient of performance, i.e., COPmat of ∼46.5 and an adiabatic temperature change of ∼10.5 K) and good cyclic stability is prepared. A thermo-mechanically coupled and crystal-plasticity-based phase field model including both the descriptions of Ni4Ti3 precipitation and martensitic transformation

Because of the huge specific surface area at the micro/nano scale, inter-surface adhesion and surface effects play a critical role in the behavior of solid-to-solid contact. The inter-surface adhesion originates from the intermolecular traction between two surfaces, while the surface effects, including residual surface stress and surface elasticity, result from the physical discrepancy between the

Miura-Ori, a celebrated origami pattern that facilitates functionality in matter, has found multiple applications in the field of mechanical metamaterials. Modifications of Miura-Ori pattern can produce curved configurations during folding, thereby enhancing its potential functionalities. Thus, a key challenge in designing generalized Miura-Ori structures is to tailor their folding patterns to achieve

The double network hydrogels (DN gels) process high fracture toughness due to their considerable energy dissipation during fracture. To effectively interpret the energy dissipation, it is imperative to conduct a study on the quantitative characterization of the dissipated energy density distribution and the damage zone around the crack tip. In this study, we propose a series of tearing tests on pre-stretched

Many blood vessels exist in brain tissue. Their internal blood pressure plays a crucial role in physiological disorders, such as brain edema, stroke, or traumatic brain injury (concussion). Homogenized continuum mechanics-based brain tissue models can provide an attractive approach to rapidly simulate blood-pressure related physiological disorders, and traumatic brain injury. These homogenized models

Traditional dielectric elastomers exhibit an unstable response when the electric field reaches a certain threshold, known as electro-mechanical instability, which significantly limits the broad application of these soft active materials. Recently, a bimodal-networked dielectric elastomer has been designed without suffering from the electro-mechanical instability due to a clear strain stiffening effect

We propose a metamaterial design principle that enables the remote switching of topological states. Dynamic breaking of space-inversion symmetry is achieved through the intricate design of magnetic spring structures within the metamaterial building blocks, whose stiffness can be remotely altered using an external magnetic field. We develop a mathematical model to predict the magnetic field-induced

In amorphous solids, shear transformations, as elementary rearrangement events operating in local regions, are intrinsically entangled with dilatation deformation, which results in the physical process of the shear band being complex. To capture such entanglement, we propose a finite-deformation continuum framework for amorphous solids by incorporating nonequilibrium thermodynamics. Within this framework

Morphing ribbons and their inverse design are usually confined to plane curves, since in most cases only the curvature is considered. Given that curvature and torsion are equally important geometric characteristics of space curves, it is urgent to propose a systematic theoretical framework for the inverse design. Toward this end, we here present a multiscale theoretical framework named biomimetic Turing

In this paper, a novel hyperelastic constitutive model for soft elastomers is developed based on the concept of the tortuous tube. This model incorporates the finite extensibility of the polymer chain, the entanglement contribution to elasticity and the non-affine micro-to-macro scale transition in a unified way. To reflect the entanglement effect and its influence on the deformation of soft elastomers

Segment motion induces interchain slippage, leading to a complex coupling between hyperelastic and viscoelastic behaviors in hydrogels. Traditional models, which treat these behaviors separately and introduce a coupling free energy, struggle to capture this visco-hyperelastic coupling mechanism accurately. In this work, we develop a visco-hyperelastic constitutive model incorporating viscoelastic contributions

Thrombosis, when occurring undesirably, disrupts normal blood flow and poses significant medical challenges. As the skeleton of blood clots, fibrin fibers play a vital role in the formation and fragmentation of blood clots. Thus, studying the deformation and fracture characteristics of fibrin fiber networks is the key factor to solve a series of health problems caused by thrombosis. This study employs

Bio-inspired heterogeneous soft materials are under rapid development due to their superior fracture and fatigue resistance. In the last few years, several kinds of fibrous soft composites in different length scales have been fabricated. However, the fracture behavior and toughening mechanism of this class of materials are still elusive. Here we develop a theoretical model for the crack tip field of

Equations are developed to describe the evolution of internal parameters entering the formulation of any criterion of unhomogeneous yielding. The evolution equations are applicable to arbitrarily oriented ellipsoidal voids. The parameters include the volume fraction of voids, the relative lengths and orientations of their axes, and their relative spacings. The evolution equations are determined in

Liquid crystal elastomers (LCEs) are composed of rod-like liquid crystal (LC) molecules (mesogens) linked into elastomeric polymer networks. They present a nematic phase with directionally ordered mesogens at room temperature and an isotropic phase with no order at high temperatures, enabling large thermal-induced deformation. As a result, LCEs have become promising candidates for new applications

We study the equilibrium of hyperelastic solids subjected to kinematic constraints on many small regions, which we call perforations. Such constraints on the displacement u are given in the quite general form u(x)∈Fx, where Fx is a closed set, and thus comprise confinement conditions, unilateral constraints, controlled displacement conditions, etc., both in the bulk and on the boundary of the body

A long-standing debate and challenge in contact mechanics is to confirm the linearity between the real contact area and load on rough surfaces as well as its proportionality. Here, we first theoretically prove the linearity between the real contact area and load on rough surfaces by considering an infinite number of surface asperities. The mechanism for such linearity is that the applied force on each

X-ray diffraction (XRD) line profile analysis is a powerful material characterization tool that has been in use for over 100 years (Etter and Dinnebier, 2014; Laue, 1901) With increases in available computing power, it is now possible to simulate X-ray diffraction experiments from atomic and meso-scale simulations. Through this work, a high-throughput framework for simulating XRD line profiles of alloyed

We present elliptic, parabolic, and hyperbolic phase field (PF) equations, referred to as EPF, PPF, and HPF, for cohesive zone model (CZM) and Linear Elastic Fracture Mechanics (LEFM) PF models. The micro viscosity and micro inertia terms result in PPF and HPF, that can be solved explicitly in time. The additional advantage of the HPF is implying a finite damage propagation speed and a more favorable

Polycarbonate is a widely used ductile glassy polymer that can undergo large strain deformation before failure. During the plastic deformation process, some mechanical energy is converted to heat, which, if the specimen is loaded at rates sufficient that the heat cannot conduct out of the material, can result in significant temperature rises that affect the mechanical response. Typically, this is expected

Curved origami featuring curved tiles can store elastic energy and bias the structure toward a desired shape when subjected to appropriate constraints. Without constraints, however, a curved origami structure generally has infinitely many degrees of freedom. For engineering applications in which a particular folding motion is desired, a great many constraints have to be introduced. One natural strategy

The slender property of shell structures causes the magnitude difference between in-plane and out-of-plane stiffness. Inspired by such a geometry-induced anisotropy phenomenon, this paper proposes a novel design approach to improve the stiffness of complex shell structures. The optimization algorithm is constructed based on two technical pillars, i.e., the explicit moving morphable components (MMC)

During evolution, various functional principles have evolved that allow plants to create predetermined breaking points for the spatially defined abscission of organs. In the plant family of cacti, some species, such as Cylindropuntia bigelovii, have fragile branch–branch junctions that serve vegetative reproduction, while in other species, such as Opuntia ficus-indica, they are very stable. The fracture

A series of experiments are performed to give insight into the mechanisms of liquid rise in a 3D dense random packing of glass spheres. A sharp knee in the log-log plot of water height h versus time t curve is observed, with an attendant change in h(t) characteristic from h∝t0.5 to h∝t0.05. This behaviour is observed for 5 choices of diameter distribution of spheres, such that the mean diameter is

Dielectric rods have been employed in various electromechanical applications, including energy harvesters and sensors. This paper develops a general framework to model large deformations in dielectric rods, considering both direct and converse flexoelectric effects. Initially, we derive the governing differential equations for a three-dimensional dielectric continuum solid to model large deformations

Hydrogel-based concretes (HBCs) are an emerging class of load-bearing composite materials consisting of inert particles joined together by micro-hydrogel joints. As HBCs can harden via sol-gel process and H2O phase changes under a freezing temperature and vacuum, they are suitable for future exterritorial constructions. Previous studies have demonstrated that the internal microstructure of the hydrogel

Spider silks have attracted significant interest due to their exceptional mechanical properties, which include a unique combination of high strength, ultimate strain, and toughness. A notable characteristic of spider silk, still debated from both mechanical and functional viewpoints, is supercontraction –a pronounced contraction of up to half its original length when an unconstrained silk thread is

Phase transforming solids are in focus of modern engineering applications due to their promising mechanical properties, which originate from a change of microstructure in stress- and temperature induced loading scenarios. The transition of respective evolution laws, describing these characteristic phase changes, between several spatial (and temporal) scales through appropriate homogenization techniques

Flexible network materials with periodic constructions of bioinspired wavy microstructures are of focusing interest in recent years, because they combine outstanding mechanical performances of low elastic modulus, high stretchability, biomimetic stress-strain responses, and strain-limiting behavior. In practical applications (e.g., bio-integrated devices and tissue engineering), small holes are often

Thermally-driven semi-crystalline polymer networks are capable to achieve both the one-way shape-memory effect and two-way shape-memory effect under stress and stress-free conditions, therefore representing an appealing class of polymers for applications requiring autonomous reversible actuation and shape changes. In these materials, the shape-memory effects are achieved by leveraging the synergistic

Photoactive nematic liquid crystal elastomers permit generation of large mechanical deformation through impingement by suitably polarized light. The light-induced deformation in this class of soft matter allows for devices such as transducers and robots that may be triggered wirelessly. While there is no ostensible direct coupling between light and electricity in nematic liquid crystal elastomers,

The layer-by-layer additive manufacturing approach results in the 3D printed composite lattice structure fails to exploit fiber reinforcement, thereby resulting in inferior mechanical qualities. To address this challenge, this study proposes a novel approach leveraging composite fused filament fabrication (FFF) printing to design modular assembled composite lattice structures. Initially, three high-performance

The mechanics of animal cells is strongly determined by stress fibers, which are contractile filament bundles that form dynamically in response to extracellular cues. Stress fibers allow the cell to adapt its mechanics to environmental conditions and to protect it from structural damage. While the physical description of single stress fibers is well-developed, much less is known about their spatial

A rate-dependent crystal-plasticity (CP) framework that captures the coupled phase transformation - plastic deformation behavior of shape memory alloys (SMAs) is presented. Here, different from previous models, the flow rule for martensitic phase transformation incorporates the entire deformation gradient for transformation, including the rotation. Predictions of transformation strain and variant selection

Ductile failure by the onset of strain localization in rate sensitive porous materials is investigated using a linear perturbation stability analysis. A micromechanics-based constitutive model accounting for inhomogeneous yielding at the micro-scale, due to plastic strain concentration in the inter-void ligaments, is used. Strain and strain rate hardening of the material is accounted for using a phenomenological

Nonlinear mechanical systems can exhibit non-uniqueness of the displacement field in response to a force field, which is related to the non-convexity of strain energy. This work proposes a Neural Network-based surrogate model capable of capturing this phenomenon while introducing an energy in a latent space of small dimension, that preserves the topology of the strain energy; this feature is a novelty

In this work, we develop a theoretical formulation for describing dissipative material behaviors in a stochastic setting, using the framework of Generalized Standard Materials (GSM). Our goal is to capture the variability inherent in the material model while ensuring thermodynamic consistency, by employing the mathematical framework of stochastic programming. We first show how average behaviors can

Machine learning methods for strut-based architected solids are attractive for reducing computational costs in optimisation calculations. However, the space of all realizable strut-based periodic architected solids is vast: not only can the number of nodes, their positions and the radii of the struts be changed but the topological variables such as the connectivity of the nodes brings significant complexity

In recent years, soft materials with reversible adhesion have come to the fore as a promising avenue of research. Compared to other reversible adhesion methods, electroadhesion enabled by the formation of ionic double layer (IDL) has been widely used due to its simplicity, low energy consumption, fast response, and reversibility. Despite the extensive experimental studies and qualitative mechanistic

Cell membrane rupture occurs universally and is long thought to be the terminal event of cell death; however, there is an inadequate understanding of the microscopic mechanisms of membrane rupture at the molecular level. In this study, we investigated the rupture mechanism of two model membranes, 1-palmitoyl-2-oleoyl-phosphatidylcholine (POPC) and cholesterol bilayer membranes, under surface tension

Explicit expressions for the free-energy and dissipation densities of viscoelastic composites at fixed temperature are proposed. The composites are comprised of an arbitrary number of distinct constituents exhibiting linear Maxwellian rheologies and distributed randomly at a length scale that is much smaller than that over which applied loads vary significantly. Central to their derivation is the recognition

Continuum solid mechanics form the foundation of numerous theoretical studies and engineering applications. Distinguished from traditional mesh-based numerical solutions, the rapidly developing field of scientific machine learning, exemplified by methods such as physics-informed neural networks (PINNs), shows great promise for the study of forward and inverse problems in mechanics. However, accurately

Serpentine structures, composed of straight and circular strips, have garnered significant attention as potential designs for flexible electronics due to their remarkable stretchability. When subjected to stretching, these serpentine strips buckle out of plane, and previous studies have identified two distinct buckling modes whose order of appearance may interchange in serpentine structures with a

The deformation of hydrogels is accompanied by water migration, a process that plays a crucial role in their fracture behaviors. Previous investigations primarily focus on how the water migration between the environment and hydrogel affects the fracture of hydrogels. Herein, a novel mechanism of the rate-dependent fracture of hydrogels induced by interior water migration is uncovered. Notched polyacrylamide

Soft materials featuring dynamic networks represent a burgeoning frontier in materials science, offering multifaceted applications spanning soft robotics, biomaterials, and flexible electronics. Unraveling the time-dependent constitutive behavior of these materials, rooted in dynamic networks, stands as a pivotal pursuit for engineering advancements. Herein, we fabricate a tough and extreme-temperature-tolerant

The design and functionality of polymeric materials hinge on failure resistance. While molecular-level details drive crack evolution in polymer networks, the connection between individual chain scission and bulk failure remains unclear and difficult to probe. In this work, we systematically study the fracture mechanics of polymer-like networks with hybrid bond strengths. We reveal that varying the

Soft-magnetorheological elastomers (s-MREs) are particulate composites made of a non-magnetic elastomeric matrix dispersed with micron-sized particles of a “soft-magnetic” material. The phenomenon of magnetostriction in specimens made from s-MREs is the change in their shape when they are subjected to an external magnetic field. Experiments in the literature show that for circular cylindrical specimens

In this paper, we extend the micromechanics-based phase-field model to simulate fatigue failure. The coupling of a micromechanics-based framework with the phase-field approach helps to differentiate between failure modes, by distinguishing between open and closed microcracks. This integrated framework links continuum field variables, such as plastic strain and damage variable, to micromechanical mechanisms

Continuum lattice grid structures which consist of joined elastic beams subject to flexural deformations are ubiquitous. In this work, we establish a theoretical framework of the topological dynamics of continuum lattice grid structures, and discover the topological edge and corner modes in these structures. We rigorously identify the infinitely many topological edge states within the bandgaps via

This work considers a recently developed finite-deformation elastoplasticity theory that assumes distinct tensorial fields describing macro-plasticity and micro-plasticity, where the latter is determined by a higher-order balance equation with associated boundary conditions. Specifically, micro-plasticity evolves according to a contribution to the Helmholtz free-energy density that depends on a Nye–Kröner-like

A systematic understanding of the toughening and self-healing mechanisms of artificial soft tissues is crucial for advancing their robust application in biomedical engineering. However, current models predominantly possess a phenomenological nature, often devoid of micromechanical intricacies and quantitative correlation between microstructure damage and macroscopic energy dissipation. To bridge this

We propose a novel variational framework to regularize softening plasticity problems. Specifically, we modify the plastic dissipation potential term by adding a contribution depending on the cumulative plastic strain-rate gradient. We formulate the evolution of the so-obtained strain-rate gradient plasticity model with an incremental variational principle. The time-discretized evolution equations are

The diffusion of hydrogen in Zircalloy fuel cladding components and its associated delayed hydride cracking (DHC) mechanism remain a bottleneck in nuclear fission. Through Crystal Plasticity Finite Element (CPFE) analysis at the grain scale (μm) and Discrete Dislocation Plasticity (DDP) at the hydride scale (nm), we explore how cladding stress history influences the dislocation network in a system

Finite deformation finite element calculations are carried out to analyze nonuniform plane strain tensile deformation of single crystals using an elastic–viscoplastic crystal plasticity constitutive relation. The planar crystals considered have two potentially active slip systems with the driving force for slip including a non-Schmid stress. The non-Schmid stress on a slip system is taken to be the

We present a formalism for developing cyclic and helical symmetry-informed machine learned force fields (MLFFs). In particular, employing the smooth overlap of atomic positions descriptors with the polynomial kernel method, we derive cyclic and helical symmetry-adapted expressions for the energy, atomic forces, and phonons, i.e., lattice vibration frequencies and modes. We use this formulation to construct