Article
Chemistry, Multidisciplinary
Varun Harbola, Samuel Crossley, Seung Sae Hong, Di Lu, Yorick A. Birkholzer, Yasuyuki Hikita, Harold Y. Hwang
Summary: Young's modulus plays a crucial role in determining the mechanical behavior of materials, particularly in flexoelectric materials where the modulus may vary nonmonotonically with thickness and be influenced by strain gradients. Nanomechanical measurements of SrTiO3 crystalline membrane drumheads reveal unexpected thickness dependence of Young's modulus, with significantly different values obtained for predominantly bending and stretching deformations in membranes thinner than 20 nm. In this regime, a strain gradient elastic coupling of around 2.2 µN is extracted, suggesting potential applications in new operational regimes of nanoelectro-mechanics.
Article
Engineering, Multidisciplinary
Sanjeev Kumar
Summary: The local scaling symmetry of the Lagrange density is used to study the electro-mechanical coupling effects in elastic dielectrics. This approach not only explains the induced polarization and electric potential, but also considers the geometric foundations. By introducing minimal replacement and the concept of gauge compensating one form field, the gauge invariance of the Lagrange density is restored. Different components of the gauge invariant energy density are constructed using scale invariant gauge curvature. Numerical simulations and validation demonstrate the effectiveness of the theory. Explorations of this kind of coupling could have significant implications in various industrial and laboratory applications.
APPLIED MATHEMATICAL MODELLING
(2024)
Article
Mathematics, Applied
Jordi Ventura, David Codony, Sonia Fernandez-Mendez
Summary: The C-0 interior penalty method proposed in this study is utilized for computational modeling of flexoelectricity and strain gradient elasticity, demonstrating stability and convergence through numerical examples in 2D and 3D cases.
JOURNAL OF SCIENTIFIC COMPUTING
(2021)
Article
Materials Science, Multidisciplinary
Kai Fang, Peng Li, Zhenghua Qian
Summary: This study systematically investigates the static and dynamic response of a piezoelectric semiconductor cantilever under transverse end force, taking into account flexoelectricity and strain gradient elasticity. Numerical case studies demonstrate the effects of characteristic length and flexoelectric coefficient on the working performance of a ZnO nanowire, revealing significant influences on electric and mechanical properties. These findings provide insight into the physical mechanisms and offer guidance for the design of piezoelectric semiconductor devices.
ACTA MECHANICA SOLIDA SINICA
(2021)
Article
Physics, Applied
Shasha Li, Yuning Li, Jingye Sun, Fang Su, Weijie Yin, Mingqiang Zhu, Tao Deng
Summary: This paper proposes a self-powered vibration sensing element based on rolled-up single-layer graphene, breaking the inversion symmetry of the single-layer graphene to achieve piezoelectricity. The device is sensitive to mechanical vibrations with different frequencies and can be used for sensing, actuating, and energy harvesting applications.
APPLIED PHYSICS LETTERS
(2021)
Article
Chemistry, Multidisciplinary
Olha Hrytsyna, Jan Sladek, Vladimir Sladek
Summary: The research utilizes non-classical linear governing equations of strain gradient piezoelectricity with micro-inertia effect to investigate Love wave propagation in a layered piezoelectric structure, examining the influence of flexoelectricity and micro-inertia effect on phase velocity. The dispersion relation for Love waves is obtained, and numerical calculations and graphical illustrations are provided for different material properties of the layer and substrate under various electric conditions. The study finds that flexoelectricity increases Love-wave phase velocity, while micro-inertia effect reduces it, especially for waves with shorter wavelengths and small guiding layer thicknesses.
Article
Materials Science, Multidisciplinary
Hui Ji, Shubao Shao, Kaiyuan Liu, Tonghui Wu, Shengping Shen, Shuwen Zhang, Minglong Xu
Summary: This study presents a mechanical design approach to enhance flexoelectricity by creating an elastic modulus gradient, and combining material design with non-uniform geometric shape, resulting in a significant improvement of the flexoelectric effect.
MECHANICS OF MATERIALS
(2022)
Article
Mechanics
Baljeet Singh, Geetika Gupta
Summary: This study investigates the effects of micro-inertia, flexoelectricity, and non-uniform strain on isotropic dielectrics and specializes the field equations for a plane. It explores the possibility of two plane waves propagating in a flexoelectric medium and examines the reflection phenomenon of plane harmonic waves from a stress-free boundary. The numerical computations and graphical illustrations of wave characteristics shed light on the influences of various factors.
MECHANICS BASED DESIGN OF STRUCTURES AND MACHINES
(2023)
Article
Mechanics
Sihao Lv, Wenjun Yang, Qian Deng, Shengping Shen
Summary: This study investigates the response of Lamb waves to a bias electric field in a nanoplate, taking into account piezoelectricity, flexoelectricity, and strain gradient elasticity. Results indicate that flexoelectricity can enhance the response of Lamb waves to external bias electric fields, and the competition between flexoelectricity and strain gradient elasticity leads to a complex variation of the voltage sensitivity with respect to the wavelength and frequency of Lamb waves.
JOURNAL OF APPLIED MECHANICS-TRANSACTIONS OF THE ASME
(2022)
Article
Materials Science, Multidisciplinary
Yicong Zheng, Liangliang Chu, Guansuo Dui, Xiang Zhu
Summary: The study computationally evaluates the role of flexoelectricity in the electromechanical response of an asymmetric micro-cylinder composed of functionally graded (FG) materials and introduces Lagrange multipliers in the mixed finite element method to understand the performance of the proposed FG micro-cylinder. Results show that a reasonable gradient function can greatly improve the mechanical and electrical properties of materials, providing new insights for optimizing the electromechanical performance of materials. The research suggests that computer simulations can help in understanding and quantifying the physical properties of flexoelectric devices.
APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING
(2021)
Article
Materials Science, Ceramics
Zhonghua Dai, Shuxuan Guo, Yun Gong, Zhiguo Wang
Summary: The study investigates the effect of doping graphite into SrTiO3 ceramic on the flexoelectric coefficient, finding that the doped material shows a significant increase in flexoelectric coefficient compared to pure STO, and introduces a new method for probing semiconductor flexoelectricity.
CERAMICS INTERNATIONAL
(2021)
Article
Mathematics, Applied
Oscar Balcells-Quintana, David Codony, Sonia Fernandez-Mendez
Summary: This paper proposes a methodology to solve high-order PDE boundary value problems with generalised periodicity using the C-0 interior penalty method. The method is developed for analyzing flexoelectricity-based metamaterial unit cells, formalizing the problem statement and weak form, and providing details on the implementation of the local and macro conditions for generalised periodicity. Numerical examples demonstrate the high-order convergence of the method and its applicability in realistic problem settings.
JOURNAL OF SCIENTIFIC COMPUTING
(2022)
Article
Chemistry, Physical
Di Guo, Pengwen Guo, Yuan Yao, Lele Ren, Mengmeng Jia, Wei Wang, Yulong Wang, Yufei Zhang, Aifang Yu, Junyi Zhai
Summary: This study demonstrates the significant enhancement of flexoelectric potential and flexotronics in single crystal silicon strips through bending, with the rate of change in Schottky barrier height increasing as the material becomes thinner. The flexoelectric polarization direction can be tuned by changing the bending direction. The working mechanism of flexoelectricity induced by the synergistic contribution of the surface piezoelectric effect and bulk flexoelectric effect is elucidated theoretically.
Article
Mechanics
Hamidreza Yademellat, Reza Ansari, Abolfazl Darvizeh, Jalal Torabi, Ali Zabihi
Summary: This study investigates the size-dependent dynamic pull-in instability of piezoelectrically and electrostatically actuated micro/nanobeams using the nonlocal strain gradient theory. The effects of flexoelectricity and piezoelectricity are considered, and various nonlinear forces are taken into account. The analysis method used in this study improves the reliability of the research model by comparing the results with existing literature.
MECHANICS BASED DESIGN OF STRUCTURES AND MACHINES
(2023)
Article
Materials Science, Multidisciplinary
Zhen Liu, Xinrong Wen, Yang Wang, Yanmin Jia, Feifei Wang, Guoliang Yuan, Yaojin Wang
Summary: By extending flexoelectricity to electrochemical functionality, it is demonstrated that flexo-catalysis effect can be achieved in centrosymmetric nanoparticles to degrade organic dyes.
ADVANCED MATERIALS TECHNOLOGIES
(2022)
Article
Mathematics, Interdisciplinary Applications
Alba Muixi, Onofre Marco, Antonio Rodriguez-Ferran, Sonia Fernandez-Mendez
Summary: This paper presents an adaptive strategy for phase-field simulations with transition to fracture, where phase-field equations are solved in small subdomains around crack tips for propagation, and an extended finite element method (XFEM) discretization is used in the rest of the domain to represent sharp cracks, reducing computational cost.
COMPUTATIONAL MECHANICS
(2021)
Article
Materials Science, Multidisciplinary
D. Codony, P. Gupta, O. Marco, I. Arias
Summary: This paper develops equilibrium equations describing the flexoelectric effect in soft dielectrics under large deformations. It formulates the model using a flexoelectric tensor defined in the material frame, leading to objective flexoelectric polarization fields. The study also includes a theory of geometrically nonlinear extensible flexoelectric rods and examines cantilever bending and buckling under mechanical and electrical actuation. The numerical implementation of the model proves to be robust in handling electromechanical instabilities in soft flexoelectric materials.
JOURNAL OF THE MECHANICS AND PHYSICS OF SOLIDS
(2021)
Article
Materials Science, Multidisciplinary
David Codony, Irene Arias, Phanish Suryanarayana
Summary: A new formulation for calculating the transversal flexoelectric coefficient of nanostructures at finite deformations is presented, using the concept of radial polarization to define the coefficient for uniform bending deformations. The flexoelectric coefficient for group IV atomic monolayers is calculated using density functional theory, revealing that graphene's coefficient is significantly larger than previously reported and operates through a different charge transfer mechanism compared to other group members.
PHYSICAL REVIEW MATERIALS
(2021)
Article
Mathematics, Applied
Jordi Ventura, David Codony, Sonia Fernandez-Mendez
Summary: The C-0 interior penalty method proposed in this study is utilized for computational modeling of flexoelectricity and strain gradient elasticity, demonstrating stability and convergence through numerical examples in 2D and 3D cases.
JOURNAL OF SCIENTIFIC COMPUTING
(2021)
Article
Engineering, Multidisciplinary
Jordi Barcelo-Mercader, David Codony, Sonia Fernandez-Mendez, Irene Arias
Summary: A formulation for weak enforcement of continuity conditions at material interfaces in high-order problems using Nitsche's method is presented, extended to impose generalized periodicity conditions at unit cell boundaries of periodic structures. Optimal high-order convergence rates are achieved with an unfitted B-spline approximation, confirming the reliability of the method.
INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING
(2022)
Editorial Material
Physics, Applied
Irene Arias, Gustau Catalan, Pradeep Sharma
JOURNAL OF APPLIED PHYSICS
(2022)
Article
Physics, Applied
D. Codony, A. Mocci, J. Barcelo-Mercader, I Arias
Summary: This paper revisits the mathematical modeling of the flexoelectric effect in the context of continuum mechanics and presents a computational technique based on B-splines to solve the associated boundary value problems. Numerical examples demonstrate the flexoelectric effect in various geometries and its application in new flexoelectric devices.
JOURNAL OF APPLIED PHYSICS
(2021)
Article
Materials Science, Multidisciplinary
A. Mocci, J. Barcelo-Mercader, D. Codony, I Arias
Summary: Through appropriate geometric design, this study introduces a class of low area-fraction, bending-dominated metamaterials that exhibit apparent piezoelectricity even when the base material is not piezoelectric. The research quantifies the apparent piezoresponse and characterizes how lattice geometry, orientation, feature size and area fraction affect it. The work provides guidelines for endowing any dielectric metamaterial with apparent piezoelectricity, leading to non-toxic, environmentally friendly, and biocompatible materials for electromechanical transduction.
JOURNAL OF THE MECHANICS AND PHYSICS OF SOLIDS
(2021)
Article
Mathematics, Applied
Oscar Balcells-Quintana, David Codony, Sonia Fernandez-Mendez
Summary: This paper proposes a methodology to solve high-order PDE boundary value problems with generalised periodicity using the C-0 interior penalty method. The method is developed for analyzing flexoelectricity-based metamaterial unit cells, formalizing the problem statement and weak form, and providing details on the implementation of the local and macro conditions for generalised periodicity. Numerical examples demonstrate the high-order convergence of the method and its applicability in realistic problem settings.
JOURNAL OF SCIENTIFIC COMPUTING
(2022)
Article
Chemistry, Multidisciplinary
Shashikant Kumar, David Codony, Irene Arias, Phanish Suryanarayana
Summary: The flexoelectric effect in fifty-four select atomic monolayers was studied using ab initio Density Functional Theory (DFT). Materials exhibited linear behavior, with TMTs having coefficients up to five times larger than graphene. The electronic origins of the flexoelectric effect were found to increase with monolayer thickness, elastic modulus along the bending direction, and sum of polarizability of constituent atoms.
Article
Engineering, Multidisciplinary
Akshay J. Thomas, Mateusz Jaszczuk, Eduardo Barocio, Gourab Ghosh, Ilias Bilionis, R. Byron Pipes
Summary: We propose a physics-guided transfer learning approach to predict the thermal conductivity of additively manufactured short-fiber reinforced polymers using micro-structural characteristics obtained from tensile tests. A Bayesian framework is developed to transfer the thermal conductivity properties across different extrusion deposition additive manufacturing systems. The experimental results demonstrate the effectiveness and reliability of our method in accounting for epistemic and aleatory uncertainties.
COMPUTER METHODS IN APPLIED MECHANICS AND ENGINEERING
(2024)
Article
Engineering, Multidisciplinary
Zhen Zhang, Zongren Zou, Ellen Kuhl, George Em Karniadakis
Summary: In this study, deep learning and artificial intelligence were used to discover a mathematical model for the progression of Alzheimer's disease. By analyzing longitudinal tau positron emission tomography data, a reaction-diffusion type partial differential equation for tau protein misfolding and spreading was discovered. The results showed different misfolding models for Alzheimer's and healthy control groups, indicating faster misfolding in Alzheimer's group. The study provides a foundation for early diagnosis and treatment of Alzheimer's disease and other misfolding-protein based neurodegenerative disorders using image-based technologies.
COMPUTER METHODS IN APPLIED MECHANICS AND ENGINEERING
(2024)
Article
Engineering, Multidisciplinary
Jonghyuk Baek, Jiun-Shyan Chen
Summary: This paper introduces an improved neural network-enhanced reproducing kernel particle method for modeling the localization of brittle fractures. By adding a neural network approximation to the background reproducing kernel approximation, the method allows for the automatic location and insertion of discontinuities in the function space, enhancing the modeling effectiveness. The proposed method uses an energy-based loss function for optimization and regularizes the approximation results through constraints on the spatial gradient of the parametric coordinates, ensuring convergence.
COMPUTER METHODS IN APPLIED MECHANICS AND ENGINEERING
(2024)
Article
Engineering, Multidisciplinary
Bodhinanda Chandra, Ryota Hashimoto, Shinnosuke Matsumi, Ken Kamrin, Kenichi Soga
Summary: This paper proposes new and robust stabilization strategies for accurately modeling incompressible fluid flow problems in the material point method (MPM). The proposed approach adopts a monolithic displacement-pressure formulation and integrates two stabilization strategies to ensure stability. The effectiveness of the proposed method is validated through benchmark cases and real-world scenarios involving violent free-surface fluid motion.
COMPUTER METHODS IN APPLIED MECHANICS AND ENGINEERING
(2024)
Article
Engineering, Multidisciplinary
Chao Peng, Alessandro Tasora, Dario Fusai, Dario Mangoni
Summary: This article discusses the importance of the tangent stiffness matrix of constraints in multibody systems and provides a general formulation based on quaternion parametrization. The article also presents the analytical expression of the tangent stiffness matrix derived through linearization. Examples demonstrate the positive effect of this additional stiffness term on static and eigenvalue analyses.
COMPUTER METHODS IN APPLIED MECHANICS AND ENGINEERING
(2024)
Article
Engineering, Multidisciplinary
Thibaut Vadcard, Fabrice Thouverez, Alain Batailly
Summary: This contribution presents a methodology for detecting isolated branches of periodic solutions to nonlinear mechanical equations. The method combines harmonic balance method-based solving procedure with the Melnikov energy principle. It is able to predict the location of isolated branches of solutions near families of autonomous periodic solutions. The relevance and accuracy of this methodology are demonstrated through academic and industrial applications.
COMPUTER METHODS IN APPLIED MECHANICS AND ENGINEERING
(2024)
Article
Engineering, Multidisciplinary
Weisheng Zhang, Yue Wang, Sung-Kie Youn, Xu Guo
Summary: This study proposes a sketch-guided topology optimization approach based on machine learning, which incorporates computer sketches as constraint functions to improve the efficiency of computer-aided structural design models and meet the design intention and requirements of designers.
COMPUTER METHODS IN APPLIED MECHANICS AND ENGINEERING
(2024)
Article
Engineering, Multidisciplinary
Leilei Chen, Zhongwang Wang, Haojie Lian, Yujing Ma, Zhuxuan Meng, Pei Li, Chensen Ding, Stephane P. A. Bordas
Summary: This paper presents a model order reduction method for electromagnetic boundary element analysis and extends it to computer-aided design integrated shape optimization of multi-frequency electromagnetic scattering problems. The proposed method utilizes a series expansion technique and the second-order Arnoldi procedure to reduce the order of original systems. It also employs the isogeometric boundary element method to ensure geometric exactness and avoid re-meshing during shape optimization. The Grey Wolf Optimization-Artificial Neural Network is used as a surrogate model for shape optimization, with radar cross section as the objective function.
COMPUTER METHODS IN APPLIED MECHANICS AND ENGINEERING
(2024)
Article
Engineering, Multidisciplinary
C. Pilloton, P. N. Sun, X. Zhang, A. Colagrossi
Summary: This paper investigates the smoothed particle hydrodynamics (SPH) simulations of violent sloshing flows and discusses the impact of volume conservation errors on the simulation results. Different techniques are used to directly measure the particles' volumes and stabilization terms are introduced to control the errors. Experimental comparisons demonstrate the effectiveness of the numerical techniques.
COMPUTER METHODS IN APPLIED MECHANICS AND ENGINEERING
(2024)
Article
Engineering, Multidisciplinary
Ye Lu, Weidong Zhu
Summary: This work presents a novel global digital image correlation (DIC) method based on a convolution finite element (C-FE) approximation. The C-FE based DIC provides highly smooth and accurate displacement and strain results with the same element size as the usual finite element (FE) based DIC. The proposed method's formulation and implementation, as well as the controlling parameters, have been discussed in detail. The C-FE method outperformed the FE method in all tested examples, demonstrating its potential for highly smooth, accurate, and robust DIC analysis.
COMPUTER METHODS IN APPLIED MECHANICS AND ENGINEERING
(2024)
Article
Engineering, Multidisciplinary
Mojtaba Ghasemi, Mohsen Zare, Amir Zahedi, Pavel Trojovsky, Laith Abualigah, Eva Trojovska
Summary: This paper introduces Lung performance-based optimization (LPO), a novel algorithm that draws inspiration from the efficient oxygen exchange in the lungs. Through experiments and comparisons with contemporary algorithms, LPO demonstrates its effectiveness in solving complex optimization problems and shows potential for a wide range of applications.
COMPUTER METHODS IN APPLIED MECHANICS AND ENGINEERING
(2024)
Article
Engineering, Multidisciplinary
Jingyu Hu, Yang Liu, Huixin Huang, Shutian Liu
Summary: In this study, a new topology optimization method is proposed for structures with embedded components, considering the tension/compression asymmetric interface stress constraint. The method optimizes the topology of the host structure and the layout of embedded components simultaneously, and a new interpolation model is developed to determine interface layers between the host structure and embedded components.
COMPUTER METHODS IN APPLIED MECHANICS AND ENGINEERING
(2024)
Article
Engineering, Multidisciplinary
Qiang Liu, Wei Zhu, Xiyu Jia, Feng Ma, Jun Wen, Yixiong Wu, Kuangqi Chen, Zhenhai Zhang, Shuang Wang
Summary: In this study, a multiscale and nonlinear turbulence characteristic extraction model using a graph neural network was designed. This model can directly compute turbulence data without resorting to simplified formulas. Experimental results demonstrate that the model has high computational performance in turbulence calculation.
COMPUTER METHODS IN APPLIED MECHANICS AND ENGINEERING
(2024)
Article
Engineering, Multidisciplinary
Jacinto Ulloa, Geert Degrande, Jose E. Andrade, Stijn Francois
Summary: This paper presents a multi-temporal formulation for simulating elastoplastic solids under cyclic loading. The proper generalized decomposition (PGD) is leveraged to decompose the displacements into multiple time scales, separating the spatial and intra-cyclic dependence from the inter-cyclic variation, thereby reducing computational burden.
COMPUTER METHODS IN APPLIED MECHANICS AND ENGINEERING
(2024)
Article
Engineering, Multidisciplinary
Utkarsh Utkarsh, Valentin Churavy, Yingbo Ma, Tim Besard, Prakitr Srisuma, Tim Gymnich, Adam R. Gerlach, Alan Edelman, George Barbastathis, Richard D. Braatz, Christopher Rackauckas
Summary: This article presents a high-performance vendor-agnostic method for massively parallel solving of ordinary and stochastic differential equations on GPUs. The method integrates with a popular differential equation solver library and achieves state-of-the-art performance compared to hand-optimized kernels.
COMPUTER METHODS IN APPLIED MECHANICS AND ENGINEERING
(2024)