Article
Mechanics
Ali Farajpour, Krzysztof Kamil Zur, Jinseok Kim, J. N. Reddy
Summary: Nanomechanical mass sensors detect ultrasmall particles by observing changes in vibration behavior due to nanoparticle attachment, incorporating strain gradient influence and nonlocality of stress components in nonlinear analysis. Nonlinear equations are solved using Hamilton's principle and perturbation technique, with verification studies and investigations into factors affecting frequency shifts.
COMPOSITE STRUCTURES
(2021)
Article
Engineering, Mechanical
Yunzhi Huang, Jian Chen, Min Zhao, Miaolin Feng
Summary: The electromechanical coupling characteristics of a double-layer piezoelectric quasicrystal micro/nano-actuator were studied, with a focus on the effects of van der Waals force and Casimir force on phonon stress and displacement. The study also revealed that the phonon-phason coupling elastic coefficient and nonlocal scale parameter have positive and negative effects on static responses.
INTERNATIONAL JOURNAL OF MECHANICAL SCIENCES
(2021)
Article
Materials Science, Composites
Zhi Ming Hu, Yu Su, Jackie Li
Summary: In this paper, a frequency-dependent micromechanics-based model is developed to study the nonlinear electromechanical coupling behaviors of ferroelectric composites, which are found to be influenced by the volume concentration, shape, and frequency of the external applied field. The modeling approach involves introducing an exponential function to evaluate certain properties of the ferroelectric phase and using a two-level micromechanics-based model to analyze the hysteresis loops and butterfly-shaped responses at different frequencies.
COMPOSITES SCIENCE AND TECHNOLOGY
(2021)
Article
Physics, Fluids & Plasmas
Mario I. Molina
Summary: The study focused on linear and nonlinear modes of a one-dimensional nonlinear electrical lattice with a fractional discrete Laplacian. Long-range intersite coupling was induced by the fractional discrete Laplacian. In the linear regime, plane waves spectrum and mean-square displacement were computed in closed form, showing ballistic behavior at long times. In the nonlinear regime, the number of generated discrete solitons decreased as the fractional exponent decreased.
Article
Engineering, Mechanical
Rafal Rusinek, Krzysztof Kecik
Summary: This paper focuses on the numerical and experimental investigation of a biomechanical system of the middle ear with an implant, aiming to assess the influence of coupling between the biomechanical and electrical system. By adding an electromechanical transducer to modify the human ear structure, the study determines the effects of voltage excitation and electromechanical coupling on implant dynamics and effectiveness. The results of this research can aid in better matching the implant to the human ear in practice.
MECHANICAL SYSTEMS AND SIGNAL PROCESSING
(2021)
Article
Engineering, Aerospace
Yaguang Wu, Yu Fan, Lin LI
Summary: This paper proposes the definition of the Nonlinear Modal Electromechanical Coupling Factor (NMEMCF) and the corresponding numerical method to quantitatively evaluate the electromechanical coupling capability of nonlinear piezoelectric structures. The NMEMCF is found to have a strong correlation with geometric parameters and energy dissipation, making it an important design indicator for piezoelectric damping.
CHINESE JOURNAL OF AERONAUTICS
(2023)
Article
Mathematics, Applied
Gabriel Acosta, Francisco Bersetche, Julio D. Rossi
Summary: This paper investigates two different ways of coupling local operators with nonlocal operators, obtaining equations related to energy functionals. Existence and uniqueness of solutions are proved by directly minimizing the related energy functionals. These ideas are then extended to local/nonlocal elasticity models coupling classical local elasticity with nonlocal peridynamics.
SIAM JOURNAL ON MATHEMATICAL ANALYSIS
(2022)
Article
Mathematics, Applied
Georgiy M. Sevastyanov
Summary: The article addresses the problem of stress relaxation in a twisted nonlinear viscoelastic rod and presents a solution, as well as discussing the decomposition of elastic and creep parts among others.
ZAMM-ZEITSCHRIFT FUR ANGEWANDTE MATHEMATIK UND MECHANIK
(2022)
Article
Energy & Fuels
Yeon-Gyeong Chae, Seok-June Chae, Su-Hwan Go, Eun-Ji Kim, Seok-Jung Park, Hyunseok Song, Sahn Nahm
Summary: The output power of piezoelectric energy harvester (PEH) depends on the electromechanical coupling factor (kp) of the piezoceramic, which can be increased by [001]-texturing. The [KN(N1-zSz)-BAZ-SZ] piezoceramics textured along [001] orientation showed a large kp of 0.77, the highest reported for KNN-related piezoceramics. A cantilever-type PEH using the [KN(N0.99S0.01)-BAZ-SZ] piezoceramic achieved a high output power density of 7.86 mW/cm(3), the highest among lead-free piezoceramics based PEHs. Therefore, [001]-textured KN(N0.99S0.01)-BAZ-SZ piezoceramic is an excellent candidate for PEH and [001]-texturing is an efficient method for developing piezoceramics for PEH.
INTERNATIONAL JOURNAL OF ENERGY RESEARCH
(2023)
Article
Mathematics, Applied
J. Gwinner, N. Ovcharova
Summary: For the first time, a nonlinear interface problem on an unbounded domain with nonmonotone set-valued transmission conditions is analyzed. The investigated problem involves a nonlinear monotone partial differential equation in the interior domain and the Laplacian in the exterior domain. By boundary integral methods, the problem is transformed and a novel hemivariational inequality (HVI) is obtained that lives on the interior domain and on the coupling boundary, only. The original variational problem is reduced to a finite dimensional problem that can be solved by standard optimization tools.
COMPUTERS & MATHEMATICS WITH APPLICATIONS
(2023)
Article
Mechanics
J. W. Xu, P. Wang, Z. H. Liu
Summary: This paper investigates the influence of flexoelectricity on the electromechanical coupling response of piezoelectric circular nanoplates with different electric boundary conditions. The results show that the flexoelectric effect has a more significant influence on the electrostatic responses than the piezoelectric effect at the nanoscale. The induced electric potential due to the flexoelectric effect may be helpful for sensing or energy harvesting designs.
Article
Multidisciplinary Sciences
Shuai Yang, Jinglei Li, Yao Liu, Mingwen Wang, Liao Qiao, Xiangyu Gao, Yunfei Chang, Hongliang Du, Zhuo Xu, Shujun Zhang, Fei Li
Summary: Textured PIN-PSN-PT ceramics fabricated using a templated grain-growth approach exhibit high k(33) values of 85 to 89% and greatly increased T-rt values of 160 to 200 degrees Celsius, making them a promising alternative to single crystals for the development of advanced piezoelectric devices.
NATURE COMMUNICATIONS
(2021)
Article
Mathematics, Applied
M. Jahangiri, M. Asghari
Summary: The non-classical continuum theory of strain gradient elasticity effectively captures small-scale effects in micro-structures. A formulation is developed to investigate the coupled torsional-flexural vibrations of micro-rotors considering inertia nonlinearities. The strain gradient theory predicts more reliable results for micro-rotors with thin shafts compared to classical continuum mechanics.
APPLIED MATHEMATICS AND COMPUTATION
(2023)
Article
Mathematics, Applied
Vitaly Kalinin, Alexander Shlapunov, Konstantin Ushenin
Summary: This study considers a mathematical model that relates to reconstructing cardiac electrical activity from ECG measurements on the body surface. By applying recent developments in solving boundary value problems for elliptic and parabolic equations in Sobolev type spaces, uniqueness theorems for the model have been obtained. These results can serve as a sound foundation for creating numerical methods for non-invasive mapping of the heart.
ZAMM-ZEITSCHRIFT FUR ANGEWANDTE MATHEMATIK UND MECHANIK
(2023)
Article
Energy & Fuels
Krzysztof Kecik, Marcin Kowalczuk
Summary: This paper investigates the possibility of converting vibrations to electricity and proposes a numerical and experimental study of a magnetic levitation harvester. The results indicate that the nonlinear electromechanical coupling model is more suitable for higher oscillations of the magnet, and recovered energy can be controlled by simple configuration of the magnet coil position.
Article
Engineering, Multidisciplinary
Ricardo Ruiz-Baier, Matteo Taffetani, Hans D. Westermeyer, Ivan Yotov
Summary: In this study, a new mixed-primal finite element scheme was proposed to solve the multiphysics model involving fluid flow and consolidation equations without the need for Lagrange multipliers. The research focused on numerical simulations related to geophysical flows and eye poromechanics, exploring different interfacial flow regimes that could help understand early morphologic changes associated with glaucoma in canine species.
COMPUTER METHODS IN APPLIED MECHANICS AND ENGINEERING
(2022)
Article
Geochemistry & Geophysics
F. Di Michele, J. May, D. Pera, V Kastelic, M. Carafa, C. Smerzini, I Mazzieri, B. Rubino, P. F. Antonietti, A. Quarteroni, R. Aloisio, P. Marcati
Summary: This paper simulates the earthquake in L'Aquila on April 6, 2009 using an open-source code called SPEED. The results show good agreement with recorded data and demonstrate the potential implications for seismic risk assessment.
GEOPHYSICAL JOURNAL INTERNATIONAL
(2022)
Article
Mathematics, Applied
Vesa Kaarnioja, Yoshihito Kazashi, Frances Y. Kuo, Fabio Nobile, Ian H. Sloan
Summary: This paper discusses the kernel-based interpolation method for approximating multivariate periodic functions, particularly in the context of uncertainty quantification for elliptic partial differential equations with a diffusion coefficient given by a periodic random field. The paper includes a complete error analysis, lattice construction details, and numerical experiments supporting the proposed theory, ensuring a convergence rate and error bound independent of dimension.
NUMERISCHE MATHEMATIK
(2022)
Article
Statistics & Probability
Eleonora Arnone, Alois Kneip, Fabio Nobile, Laura M. Sangalli
Summary: This paper examines the consistency of the estimator in a spatial regression with partial differential equation (PDE) regularization. By using the finite-element method to obtain an approximate solution, the paper investigates the consistency, bias, and variance of the estimators with respect to sample size and the value of the smoothing parameter.
Article
Mathematics, Applied
Gabriel N. Gatica, Bryan Gomez-Vargas, Ricardo Ruiz-Baier
Summary: In this paper, the a posteriori error analysis for mixed-primal and fully-mixed finite element methods approximating the stress-assisted diffusion of solutes in elastic materials is developed. Two efficient and reliable residual-based a posteriori error estimators are derived and their performance is confirmed through numerical tests, illustrating the effectiveness of adaptive mesh refinement.
JOURNAL OF COMPUTATIONAL AND APPLIED MATHEMATICS
(2022)
Article
Mathematics, Applied
N. A. Barnafi, B. Gomez-Vargas, W. J. Lourenco, R. F. Reis, B. M. Rocha, M. Lobosco, R. Ruiz-Baier, R. Weber dos Santos
Summary: In this paper, we propose a novel coupled poroelasticity-diffusion model that considers the formation process of extracellular edema and infectious myocarditis under large deformations. The model takes into account the interaction between interstitial flow and the immune-driven dynamics between leukocytes and pathogens. A numerical approximation scheme using five-field finite element method is developed and stability analysis is conducted. The computational tests demonstrate the properties of the model and finite element schemes.
JOURNAL OF SCIENTIFIC COMPUTING
(2022)
Article
Computer Science, Interdisciplinary Applications
Christian Vergara, Simone Stella, Massimiliano Maines, Pasquale Claudio Africa, Domenico Catanzariti, Cristina Dematte, Maurizio Centonze, Fabio Nobile, Alfio Quarteroni, Maurizio Del Greco
Summary: This study assessed a computational tool for estimating electrical activation in the left ventricle of patients with left bundle branch block and possible myocardialfibrosis, with a focus on the latest electrically activated segment (LEAS). The results showed that the tool was able to accurately reproduce electrical activation maps and had excellent agreement in LEAS location.
MEDICAL & BIOLOGICAL ENGINEERING & COMPUTING
(2022)
Article
Physiology
Wesley de Jesus Lourenco, Ruy Freitas Reis, Ricardo Ruiz-Baier, Bernardo Martins Rocha, Rodrigo Weber dos Santos, Marcelo Lobosco
Summary: This paper investigates the formation of myocardial edema in acute infectious myocarditis and modifies a model to describe the associated dynamics. Computational methods can provide insights into the relationship between pathogens and the immune system, shedding light on the variations in myocarditis inflammation among different patients.
FRONTIERS IN PHYSIOLOGY
(2022)
Article
Computer Science, Interdisciplinary Applications
Wietse M. Boon, Martin Hornkjol, Miroslav Kuchta, Kent-Andre Mardal, Ricardo Ruiz-Baier
Summary: This paper advances the analysis of discretizations for a fluid-structure interaction model, proposing a five-field mixed-primal finite element scheme and deriving adequate inf-sup conditions. The stability of the formulation is established robustly in all material parameters and its performance is corroborated by several test cases.
JOURNAL OF COMPUTATIONAL PHYSICS
(2022)
Article
Mathematics, Applied
Fabio Nobile, Tommaso Vanzan
Summary: This manuscript investigates the discretization of robust quadratic optimal control problems under uncertainty. It proposes efficient preconditioners and estimates the dependence of the spectrum of the preconditioned system matrix on the statistical properties. Numerical experiments confirm the theoretical results.
NUMERICAL LINEAR ALGEBRA WITH APPLICATIONS
(2023)
Article
Engineering, Biomedical
Michele Bucelli, Alberto Zingaro, Pasquale Claudio Africa, Ivan Fumagalli, Luca Dede', Alfio Quarteroni
Summary: We have developed a mathematical and numerical model that simulates the various processes involved in heart function, including electrophysiology, mechanics, and hemodynamics. The model also considers the interactions between the different processes, such as electro-mechanical and mechano-electrical feedback. By using a coupled fluid-structure interaction approach, we are able to represent the three-dimensional nature of the heart muscle and hemodynamics. The model has been validated using a realistic human left heart model and shows qualitative and quantitative agreement with physiological ranges and medical images.
INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN BIOMEDICAL ENGINEERING
(2023)
Article
Engineering, Multidisciplinary
Dimitri Goutaudier, Fabio Nobile, Jurg Schiffmann
Summary: In this paper, an ordered reduced basis interpolation (ORBI) technique is proposed to improve the adaptation accuracy and computational efficiency of the POD basis. By considering more information in the construction of the interpolation operator, the proposed method is more accurate than the ITSGM method at a similar computation cost. Trained at only three points of the parameters space, the developed h-ROM performs much faster simulations with satisfactory accuracy even far from the training points.
INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING
(2023)
Article
Mathematics, Applied
Yoshihito Kazashi, Fabio Nobile
Summary: The paper presents a kernel method for estimating a probability density function from an independent and identically distributed sample. The estimator is a linear combination of kernel functions with coefficients determined by a linear equation. An error analysis is conducted for the mean integrated squared error in a general reproducing kernel Hilbert space setting. The developed theory is then applied to estimate probability density functions in weighted Korobov spaces, achieving a dimension-independent convergence rate close to the optimal rate. Numerical results validate the theory.
SIAM JOURNAL ON NUMERICAL ANALYSIS
(2023)
Article
Mathematics, Interdisciplinary Applications
Juan P. Madrigal-Cianci, Fabio Nobile, Raul Tempone
Summary: In this work, a class of multilevel Markov chain Monte Carlo (ML-MCMC) algorithms based on independent Metropolis-Hastings proposals is presented, analyzed, and implemented for Bayesian inverse problems. The algorithm aims to construct highly coupled Markov chains together with the standard multilevel Monte Carlo method to achieve better cost-tolerance complexity. The effectiveness of the proposed method is demonstrated through convergence analysis and numerical experiments on various academic examples.
SIAM-ASA JOURNAL ON UNCERTAINTY QUANTIFICATION
(2023)