Article
Chemistry, Physical
Vidar Skogvoll, Jonas Ronning, Marco Salvalaglio, Luiza Angheluta
Summary: Topological defects and smooth excitations play crucial roles in determining the properties of systems exhibiting collective order. We propose a generic non-singular field theory that provides a comprehensive description of defects and excitations in systems with O(n) broken rotational symmetry. By employing this formalism, we investigate fast events, including defect nucleation/annihilation and dynamical phase transitions, where the interplay between topological defects and nonlinear excitations is particularly significant. We showcase the versatility of our approach by applying it to various systems such as Bose-Einstein condensates, active nematics, and crystal lattices.
NPJ COMPUTATIONAL MATERIALS
(2023)
Article
Construction & Building Technology
M. Taleb, D. Bulteel, D. Betrancourt, F. Roudet, S. Remond, A. Montagne, D. Chicot
Summary: In order to make the cementitious ink suitable for printing, it needs to have contradictory properties - fluid enough to be pumpable and extrudable initially, but quick to stiffen after deposition for buildability. This study aims to compare experimental protocols for mechanical characterization and assess the drop in bond strength with different printing parameters. Classical microindentation tests and a new method for multidirectional compression testing were conducted. Results validate the new experimental procedure and show a weakening and widening of the interface over time, as well as anisotropy in multidirectional compression tests and lower adherence with a larger time gap between layers in instrumented macroindentation.
MATERIALS AND STRUCTURES
(2023)
Article
Construction & Building Technology
Richard Caron, Ravi A. Patel, Andreas Bogner, Frank Dehn
Summary: In this study, multi-scale experiments and analytical micro-mechanics based modeling were conducted to evaluate the Young's modulus of alkali-activated slag (AAS) concrete. The evolution of phase volume fractions was obtained using a thermodynamic model coupled with a kinetic model. Nano-indentation measurements revealed the presence of a soft and a hard matrix made of reaction products, regardless of the mix composition. The homogenization model for Young's modulus was validated with over 95% accuracy against results on paste and concrete. Sensitivity analysis showed that the Young's modulus of the aggregates and the soft matrix were the main influencing parameters.
CONSTRUCTION AND BUILDING MATERIALS
(2023)
Article
Chemistry, Physical
Shu-Wen W. Chen, Jean-Marie Teulon, Harinderbir Kaur, Christian Godon, Jean-Luc Pellequer
Summary: Measuring the structural stiffness is a method to study the elastic response of materials under external indentation, with the goal of revealing how nanostructured components or physiological circumstances affect the material's elastic behavior. In this study, atomic force microscopy (AFM) was used with a nano-scale pyramidal tip to indent the surfaces of polyacrylamide gels and Arabidopsis thaliana seedling roots with different softness. The stiffness-depth curve derived from the measured force showed heterogeneous elasticity. The responding force was decomposed into depth-impact, Hookean, and tip-shape components, called trimechanic, allowing the researchers to observe how these three restoring nanomechanics change with depth. The trimechanic theory provides insights into the restoring nanomechanics of indented materials and can differentiate the softness between different gel categories.
NANOSCALE HORIZONS
(2023)
Article
Materials Science, Multidisciplinary
L. Kurpaska, F. J. Dominguez-Gutierrez, Y. Zhang, K. Mulewska, H. Bei, W. J. Weber, A. Kosinska, W. Chrominski, I Jozwik, R. Alvarez-Donado, S. Papanikolaou, J. Jagielski, M. Alava
Summary: Significant hardening effect due to Fe concentrations in Ni-based alloys with face-centered-cubic structure has been studied. The main strengthening factors are sluggish dislocation diffusion, reduced defect sizes and the nucleation of stacking faults.
MATERIALS & DESIGN
(2022)
Article
Engineering, Mechanical
Wenlong Tian, Lehua Qi, M. W. Fu
Summary: A multi-scale and multi-step Mean-Field Homogenization method is proposed to predict the Effective Thermal Conductivities (ETCs) of Three-Dimensional (3D) braided composites. The method decomposes the composites into pseudo-grains and sequentially predicts the ETCs. The results show that the ETCs of the composites are influenced by fiber volume fraction, transverse ETC, and interior braiding angle.
INTERNATIONAL JOURNAL OF MECHANICAL SCIENCES
(2022)
Article
Engineering, Mechanical
Mohammad Aramfard, Francisco Perez-Rafols, Lucia Nicola
Summary: A seamless 2D dual-scale computational scheme has been developed to study contact problems, combining an atomistic domain for contact interaction description and an elastic continuum domain. The innovative scheme is validated against full atomistic simulations and used to investigate the effect of adhesion on scratching processes.
TRIBOLOGY INTERNATIONAL
(2022)
Article
Chemistry, Physical
Zara Moleinia, David F. Bahr
Summary: This research focuses on simulating and predicting the thermomechanical responses of metallic nano-layers in crystal plasticity large deformation finite element platforms using multi-scale approaches. By studying nano- and homogenized scales, appropriate constitutive models are developed and computational methods are proposed to accelerate and optimize the model validation process.
Article
Chemistry, Multidisciplinary
Takashi Sumigawa, Takahiro Shimada, Kai Huang, Yuki Mizuno, Yohei Hagiwara, Naoki Ozaki, Takayuki Kitamura
Summary: Crystal defects, specifically dislocations, play a crucial role in brittle fracture of materials. This study investigates the fracture mechanism of dislocations in SrTiO3 through atomic-level observations and theoretical evaluations, revealing a lower fracture strength and quantitatively evaluating the fracture toughness of dislocation-induced cracks.
Article
Mathematics, Interdisciplinary Applications
Hao Shen, Emmanuel Brousseau, Sivakumar Kulasegaram
Summary: Nano-indentation tests are important in material science, and the possibility of using smooth particle hydrodynamics (SPH) to model the process is explored in this paper. The SPH modeling of nano-indentation is validated using published studies and compared to finite element modeling and experimental results. The results suggest that SPH is a potential technique for investigating high strain deformation phenomena on the nanoscale.
COMPUTATIONAL PARTICLE MECHANICS
(2023)
Article
Materials Science, Multidisciplinary
Yin Zhang, Kunqing Ding, Sandra Stangebye, Dengke Chen, Josh Kacher, Olivier Pierron, Ting Zhu
Summary: Dislocation nucleation plays a crucial role in the plastic deformation of crystalline materials. However, accurately predicting the mode and rate of dislocation nucleation under typical experimental loading conditions through molecular dynamics simulation is challenging due to timescale limitations. In this study, the researchers used the free-end nudged elastic band method to determine the activation energies and activation volumes of dislocation nucleation in four typical face-centered cubic metals. Their focus was on surface and grain boundary dislocation nucleation processes. The atomistically determined activation volumes of these processes were found to be larger than 10b(3) under typical experimental loading conditions. The results were then compared with experimentally measured activation volumes in ultrafine-grained and nanocrystalline metals, providing mechanistic insight into their rate-controlling deformation mechanisms.
Article
Materials Science, Multidisciplinary
Eduardo A. Barros de Moraes, Jorge L. Suzuki, Mohsen Zayernouri
Summary: Materials inherently contain defects that affect mechanical behavior, and understanding the evolution of these defects is essential for multi-scale coupling. A graph-based surrogate model is developed for computing stochastic dislocation mobility, providing efficient propagation of material parameters and uncertainties across scales. The model allows for fast and accurate estimation of atomistic mobility, improving computational speed and accuracy.
COMPUTATIONAL MATERIALS SCIENCE
(2021)
Article
Engineering, Electrical & Electronic
Tian Zhong, Feng Guo, Shiyun Lei, Biao Xiao, Qingduan Li, Tao Jia, Xunchang Wang, Renqiang Yang
Summary: This study systematically evaluates the multi-scale mechanical properties of bulk-heterojunction (BHJ) films containing three representative electron acceptors. It is found that the films based on PC71BM, Y6, and PRi-C39 show sequential decreases in tensile modulus and increases in fracture strain and toughness. The nanoindentation moduli of the films based on these acceptors also vary accordingly. Creep analyses reveal a sequential decrease in creep deformation occurrence for the PC71BM, Y6, and PRi-C39-based films. Contact angle tests demonstrate that donor-acceptor interactions greatly affect the mechanical properties of these films. These findings highlight the importance of acceptor type in the multi-scale mechanical properties of BHJ films for the development of reliable flexible polymer solar cells (PSCs).
NPJ FLEXIBLE ELECTRONICS
(2023)
Article
Geochemistry & Geophysics
Yanni Chen, Jose Lizarraga, Giuseppe Buscarnera
Summary: The article discusses a multi-scale modeling approach that considers rock microstructure, hydraulic conductivity, and pore compaction to explain the delay in subsurface subsidence and the hydro-mechanical coupling related to inelastic compaction. A constitutive model within the framework of breakage mechanics is proposed to link hydraulic conductivity with inelastic deformations caused by injection-depletion cycles. Numerical results show that the model allows isolating near-field and far-field effects in the computation of land subsidence and can generate forecasts for different modeling scenarios.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2021)
Article
Engineering, Mechanical
Dongping Zhu, Wei Zhang, Zhixia Ding
Summary: Dislocation accumulation caused by crystallographic slip or plastic flow is a critical factor in fatigue crack growth. The evolution of mobile and immobile dislocation densities in different loading conditions has been investigated. A fatigue crack nucleation criterion is proposed, which is correlated with the Coffin-Manson relationship.
JOURNAL OF ENGINEERING MECHANICS
(2022)
Article
Materials Science, Multidisciplinary
Rajat Arora, Amit Acharya
JOURNAL OF THE MECHANICS AND PHYSICS OF SOLIDS
(2020)
Article
Materials Science, Multidisciplinary
Sabyasachi Chatterjee, Giacomo Po, Xiaohan Zhang, Amit Acharya, Nasr Ghoniem
JOURNAL OF THE MECHANICS AND PHYSICS OF SOLIDS
(2020)
Article
Mathematics, Applied
Chiqun Zhang, Amit Acharya, Alan C. Newell, Shankar C. Venkataramani
Summary: Defects in ordered media are a common feature with universal characteristics, but often appear as 'unphysical' singularities in macroscopic models. Researchers have developed a method to enrich coarse-grained theories to study the dynamics and interactions of defects in extended systems. Their approach is applicable for energy driven behaviors of defects in various types of crystalline materials.
PHYSICA D-NONLINEAR PHENOMENA
(2021)
Article
Engineering, Multidisciplinary
Leo Morin, Amit Acharya
Summary: This study develops a computational model for arbitrary brittle crack propagation within a fault-like layer in a 3D elastic domain, and analyzes its associated quasi-static and dynamic fields. The model utilizes FFT-based solver for linear momentum balance and a Godunov-type projection-evolution method for crack evolution equation. Applications of the model include exploring equilibria, irreversibility, strength and toughness criteria, and crack propagation under different loading conditions.
COMPUTER METHODS IN APPLIED MECHANICS AND ENGINEERING
(2021)
Article
Materials Science, Multidisciplinary
Amit Acharya
Summary: An action functional is developed for nonlinear dislocation dynamics, aiming to use effective field theory to describe the macroscopic behavior of plasticity in crystalline solids. This work reveals connections between continuum mechanics, material science of defects in solids, effective field theory techniques in physics, and fracton tensor gauge theories.
JOURNAL OF THE MECHANICS AND PHYSICS OF SOLIDS
(2022)
Article
Mathematics, Applied
Janusz Ginster, Amit Acharya
Summary: This article extends a fundamental result of continuum mechanics and answers a fundamental question in the recent nonlinear elastic theory of dislocations. The implication of the result in the nonlinear theory is different from its counterpart in the linear theory. The result is generalized to matrix fields with non-vanishing curl and it is shown that a matrix field with constant curl is necessarily constant. Additionally, it is proved that a measurable rotation field is as regular as its distributional curl allows.
ARCHIVE FOR RATIONAL MECHANICS AND ANALYSIS
(2022)
Article
Materials Science, Multidisciplinary
Amit Acharya, Luiza Angheluta, Jorge Vinals
Summary: This paper discusses the inherent inconsistency in identifying the phase field in the phase field crystal theory with the material mass and distortion, and presents two alternative theories to remedy this issue.
MODELLING AND SIMULATION IN MATERIALS SCIENCE AND ENGINEERING
(2022)
Article
Materials Science, Multidisciplinary
Abhishek Arora, Rajat Arora, Amit Acharya
Summary: This study demonstrates the significantly different responses of metal thin films in compression and shear, and successfully simulates this behavior using the Mesoscale Field Dislocation Mechanics (MFDM) model without any modification or additional fitting parameters. This research represents a crucial theoretical advancement in the field of strain gradient plasticity models.
Article
Chemistry, Physical
Saptarshi Saha, Amit Acharya, Gerald J. Wang
Summary: This paper introduces a new algorithm, called the topology-accommodating direction assignment (TADA) algorithm, which can identify topological defects in liquid crystalline materials. By assigning a unique vector to each mesogen, the concept of the liquid crystal director field is extended to the scale of mesogens. The algorithm identifies line segments along which this assigned vector field is discontinuous, with the defects located at the termination points of these line segments, and can identify the mere presence of defects by searching far away from them.
JOURNAL OF CHEMICAL THEORY AND COMPUTATION
(2023)
Article
Mathematics, Applied
Amit Acharya, Marshall Slemrod
Summary: This paper examines a system of partial differential equations describing dislocation dynamics in a crystalline solid. In particular, it considers dynamics linearized about a state of zero stress and uses linear semigroup theory to establish existence, uniqueness, and time-asymptotic behavior of the linear system.
QUARTERLY OF APPLIED MATHEMATICS
(2023)
Article
Engineering, Multidisciplinary
Amit Acharya
Summary: A dual variational principle is proposed for the nonlinear system of PDEs describing the dynamics of dislocations in elastic solids. The dual variational principle accounting for a specified set of initial and boundary conditions for a general class of PDEs is also developed.
JOURNAL OF ELASTICITY
(2023)
Article
Materials Science, Multidisciplinary
Siddharth Singh, He Liu, Rajat Arora, Robert M. Suter, Amit Acharya
Summary: A rigorous methodology is developed to compute the elastic fields generated by defect structures within grains in a polycrystal that has undergone tensile extension. An example application is made using a near-field high energy x-ray diffraction microscope measurement of a zirconium sample that experienced 13.6% tensile extension. The elastic fields of these identified features are calculated by identifying apparent disclination line defects in (sub)grain boundary features.
MODELLING AND SIMULATION IN MATERIALS SCIENCE AND ENGINEERING
(2023)
Article
Materials Science, Multidisciplinary
Amit Acharya, Jorge Vinals
Article
Engineering, Multidisciplinary
Sabyasachi Chatterjee, Amit Acharya
INTERNATIONAL JOURNAL FOR MULTISCALE COMPUTATIONAL ENGINEERING
(2020)
Article
Mechanics
Amit Acharya
COMPTES RENDUS MECANIQUE
(2020)
Article
Materials Science, Multidisciplinary
Yanzheng Wang, Qian Wu, Yiran Tian, Guoliang Huang
Summary: This paper proposes the microstructure design of an odd plate and investigates the directional wave energy amplification and the presence of interface waves in odd plates through theoretical and numerical analysis. The research findings contribute to the understanding of elastic behavior in 2D non-Hermitian systems.
JOURNAL OF THE MECHANICS AND PHYSICS OF SOLIDS
(2024)
Article
Materials Science, Multidisciplinary
F. Greco, D. Codony, H. Mohammadi, S. Fernandez-Mendez, I. Arias
Summary: This study overcomes the difficulty of harnessing the flexoelectric effect by designing multiscale metamaterials. Through topology optimization calculations, we obtain optimal structures for various apparent piezoelectric properties and find that low-area-fraction lattices are the preferred choice. The results show competitive estimations of apparent piezoelectricity compared to reference materials such as quartz and PZT ceramics.
JOURNAL OF THE MECHANICS AND PHYSICS OF SOLIDS
(2024)
Article
Materials Science, Multidisciplinary
Xiaoxuan Zhang, Tryaksh Gupta, Zhenlin Wang, Amalie Trewartha, Abraham Anapolsky, Krishna Garikipati
Summary: This study presents a computational framework for coupled electro-chemo-(nonlinear) mechanics at the particle scale in solid-state batteries, including interfacial fracture, degradation in charge transfer, and stress-dependent kinetics. The discontinuous finite element method allows for arbitrary particle shapes and geometries.
JOURNAL OF THE MECHANICS AND PHYSICS OF SOLIDS
(2024)
Article
Materials Science, Multidisciplinary
Chengguan Zhang, Xavier Balandraud, Yongjun He
Summary: The coexistence of both austenite and martensite is a common characteristic in Shape Memory Alloys (SMAs). The multiple-domain microstructures, consisting of austenite, martensite twins, and individual martensite variants, evolve collectively during the phase transformation, affecting the material's macroscopic response. This paper presents an experimentally observed interface consisting of five domains in a Ni-Mn-Ga single-crystal, and analyzes the effects of thermal loading path and material initial state on the domain pattern formation.
JOURNAL OF THE MECHANICS AND PHYSICS OF SOLIDS
(2024)
Article
Materials Science, Multidisciplinary
Shaobao Liu, Haiqian Yang, Guang-Kui Xu, Jingbo Wu, Ru Tao, Meng Wang, Rongyan He, Yulong Han, Guy M. Genin, Tian Jian Lu, Feng Xu
Summary: The balance between stress and adhesion plays a crucial role in governing the behaviors of adherent cells, such as cell migration. In certain microenvironments, such as tumor, variations in hydrostatic pressure can significantly impact cell volume and adhesion, which in turn affects cell behavior.
JOURNAL OF THE MECHANICS AND PHYSICS OF SOLIDS
(2024)
Article
Materials Science, Multidisciplinary
Xun Xiong, Qinglei Zeng, Yonghuan Wang, Ying Li
Summary: In this work, the authors investigate the possibility of enhancing the resistance to crack growth in brittle materials through microstructure design. They establish a computational framework to simulate crack propagation and characterize fracture energy. The effects of different types of voids on toughening mechanisms are explored, and the critical conditions for embrittlement-toughening transition are identified. The study also discusses the difference between void toughening in brittle and ductile materials, and extends the toughening strategy to nacre-like materials.
JOURNAL OF THE MECHANICS AND PHYSICS OF SOLIDS
(2024)
Article
Materials Science, Multidisciplinary
Huan Wang, Yong-Quan Liu, Jiu-Tao Hang, Guang-Kui Xu, Xi-Qiao Feng
Summary: This study establishes a cytoarchitectural model to accurately capture the buckling and postbuckling behaviors of epithelia under fast compression. The stress evolution of epithelia is divided into three stages: loading, phase transition, and stress recovery. The postbuckling process is governed by the active tension generated by the actomyosin network. The study also proposes a minimal model that predicts the flattening time and stress recovery extent as functions of applied strain or strain rate, in agreement with simulations and experiments.
JOURNAL OF THE MECHANICS AND PHYSICS OF SOLIDS
(2024)
Article
Materials Science, Multidisciplinary
Lei Liu, Hao Liu, Yuming He, Dabiao Liu
Summary: This study investigates the mechanics and topologically complex morphologies of twisted rubber filaments using a combination of experiment and finite strain theory. A finite strain theory for hyperelastic filaments under combined tension, bending, and torsion has been established, and an experimental and theoretical morphological phase diagram has been constructed. The results accurately determine the configuration and critical points of phase transitions, and the theoretical predictions agree closely with the measurements.
JOURNAL OF THE MECHANICS AND PHYSICS OF SOLIDS
(2024)
Article
Materials Science, Multidisciplinary
Abhishek Painuly, Kunnath Ranjith, Avinash Gupta
Summary: This paper analyzes the interfacial waves caused by frictional slipping and studies their dispersion relation and wave modes. By studying the slip waves in a geophysical model, the surface wave dispersion phenomenon is explored, and an alternative explanation is proposed.
JOURNAL OF THE MECHANICS AND PHYSICS OF SOLIDS
(2024)
Article
Materials Science, Multidisciplinary
Houlin Xu, Joshua Vievering, Hoang T. Nguyen, Yupeng Zhang, Jia-Liang Le, Zdenek P. Bazant
Summary: Motivated by the extraordinary strength of nacre, this study investigated the probabilistic distribution of fishnet strength using Monte Carlo simulations and found that previous analytical solutions are not applicable for fishnets with a large number of links. By approximating large-scale fishnets as a continuum with cracks or holes, the study revealed that the strength distribution follows the Weibull distribution. This new model has significance for optimizing the strength-weight ratio in printed material structures.
JOURNAL OF THE MECHANICS AND PHYSICS OF SOLIDS
(2024)
Article
Materials Science, Multidisciplinary
Souhayl Sadik, Arash Yavari
Summary: This paper revisits the mathematical foundations of nonlinear viscoelasticity and studies the geometry of viscoelastic deformations. It discusses the decomposition of the deformation gradient into elastic and viscous distortions and concludes that the viscous distortion can only be a two-point tensor. The governing equations of nonlinear viscoelasticity are derived and the constitutive and kinetic equations for various types of viscoelastic solids are discussed.
JOURNAL OF THE MECHANICS AND PHYSICS OF SOLIDS
(2024)
Article
Materials Science, Multidisciplinary
Wen Cheng, Hongkuan Zhang, Yu Wei, Kun Wang, Gengkai Hu
Summary: In this study, we propose a phenomenon similar to Thouless pumping for a continuous in-plane elastic system, enabling topological transport of elastic waves through spatial modulation of material elasticity. By incorporating specific lattice microstructures, termed pentamode materials, precise and robust control over elastic wave propagation is achieved.
JOURNAL OF THE MECHANICS AND PHYSICS OF SOLIDS
(2024)
Article
Materials Science, Multidisciplinary
Linda Werneck, Mertcan Han, Erdost Yildiz, Marc-Andre Keip, Metin Sitti, Michael Ortiz
Summary: We have developed a simple model that describes the ionic current through neuronal membranes by considering the membrane potential and extracellular ion concentration. The model combines a simplified Poisson-Nernst-Planck model of ion transport through individual ion channels with channel activation functions calibrated from experimental data. The calibrated model accounts for the transport of calcium, sodium, potassium, and chloride and shows remarkable agreement with experimentally measured current-voltage curves for human neural cells.
JOURNAL OF THE MECHANICS AND PHYSICS OF SOLIDS
(2024)
