Article
Multidisciplinary Sciences
Xuanyu Huang, Tengfei Li, Jin Wang, Kai Xia, Zipei Tan, Deli Peng, Xiaojian Xiang, Bin Liu, Ming Ma, Quanshui Zheng
Summary: This study achieves robust structural superlubricity state between microscale graphite flakes and nanostructured silicon surfaces under ambient conditions. The friction is always less than 1 mu N, the differential friction coefficient is on the order of 10(-4), without observable wear. This is attributed to the edge warping of graphite flake on the nanostructured surface under concentrated force, which eliminates the edge interaction between the graphite flake and the substrate.
NATURE COMMUNICATIONS
(2023)
Article
Materials Science, Multidisciplinary
Joseph M. Monti, Lars Pastewka, Mark O. Robbins
Summary: Surface roughness affects the contact area and geometry of solids. Small contact patches have simple geometries and low pressure, while larger contact patches have higher pressure and can be ramified with regions out of contact. Bubbles also affect the area and perimeter of contact patches.
JOURNAL OF THE MECHANICS AND PHYSICS OF SOLIDS
(2022)
Article
Engineering, Mechanical
Fernando J. Alamos, Martin Philo, David B. Go, Steven R. Schmid
Summary: This study simulated the contact between a single asperity/rigid tool under constant pressure using finite element modeling and design of experiments, and derived a new contact area expression based on characteristic time of asperity deformation.
TRIBOLOGY INTERNATIONAL
(2021)
Article
Engineering, Mechanical
Ryo Kikuuwe
Summary: This paper proposes a new concise mathematical model for describing the dynamics of gear transmission with asymmetric load-dependent friction. The model captures static friction and non-backdrivability accurately, and is applicable to different types of transmissions.
MECHANISM AND MACHINE THEORY
(2023)
Article
Computer Science, Interdisciplinary Applications
Eike Hermann Muller
Summary: The solution of time dependent differential equations with neural networks has recently received significant attention. The central idea is to learn the governing laws of the solution's evolution from data, which may contain random noise. However, unlike other machine learning applications, there is usually a wealth of knowledge about the system. This paper presents an alternative approach that incorporates conservation laws into the neural network architecture using Noether's Theorem, leading to improved predictions for three model systems.
JOURNAL OF COMPUTATIONAL PHYSICS
(2023)
Article
Engineering, Mechanical
Fernando J. Alamos, Martin Philo, David B. Go, Steven R. Schmid
Summary: A pressing concern in superplastic forming (SPF) is the ability to quantitatively model to effectively design tooling and assess process viability. Current finite element method simulations for SPF generally do not include the evolutionary nature of friction under creep conditions. In this study, a new microcontact model of a rough surface in contact with a rigid flat surface is created to predict asperity flattening under creep behavior. Additionally, a semi-empirical equation is established to predict the real contact area and friction at different SPF conditions.
TRIBOLOGY INTERNATIONAL
(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
Engineering, Multidisciplinary
Bastien Chaudet-Dumas
Summary: This work focuses on shape optimization in contact mechanics, using regularized versions of the variational inequality. By introducing shape derivatives based on directional derivatives, a gradient-based topology optimization algorithm is developed. Mesh-cutting technique is used to give an explicit representation of the shape at each iteration, facilitating the application of boundary conditions on the contact zone. Numerical results on benchmarks validate the proposed approach.
INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING
(2023)
Article
Physics, Fluids & Plasmas
Joseph M. Monti, Lars Pastewka, Mark O. Robbins
Summary: Resolving atomic scale details while capturing long-range elastic deformation remains the principal difficulty in solving contact mechanics problems with computer simulations. A numerically efficient dynamic Green's function technique has been developed to treat realistic, time-evolving, elastic solids, significantly accelerating molecular dynamics simulations of large elastic substrates. This technique has been successfully applied to single asperity contact, impact, and sliding friction problems.
Article
Mechanics
Emilio Barchiesi, Francesco dell'Isola, Pierre Seppecher, Emilio Turco
Summary: This paper investigates the properties of Duoskelion structures and compares the results with a discrete model formulation.
EUROPEAN JOURNAL OF MECHANICS A-SOLIDS
(2023)
Article
Chemistry, Multidisciplinary
Wanhao Cai, Jakob T. Bullerjahn, Max Lallemang, Klaus Kroy, Bizan N. Balzer, Thorsten Hugel
Summary: In this study, stereographic force spectroscopy was established to investigate the single-bond strength at different pulling angles. The results showed that the bond strength increased with increasing pulling angle, indicating a mechanical anisotropy of the chemical bond.
Article
Physics, Multidisciplinary
Piotr Ogonowski
Summary: By combining the continuum mechanics with Einstein's field equations, the classic relativistic description, curvilinear description, and quantum description of the physical system can be reconciled using the proposed Alena Tensor. The method allows for further development with additional fields.
FRONTIERS IN PHYSICS
(2023)
Article
Mathematics, Interdisciplinary Applications
Jana Wedel, Mitja Strakl, Matjaz Hribersek, Paul Steinmann, Jure Ravnik
Summary: In computational studies of particulate multiphase flow systems, considering particle-particle and particle-wall collisions is crucial, especially for nonspherical particles. This study presents an efficient numerical implementation of a novel superellipsoidal particle collision model, which can represent various shapes by adjusting shape parameters. The study also introduces a fast and stable Newton-Raphson-based method for modeling frictional collisions of nonspherical superellipsoidal particles and demonstrates its performance.
COMPUTATIONAL PARTICLE MECHANICS
(2023)
Article
Multidisciplinary Sciences
Yuanzhe Li, Pengpeng Bai, Hui Cao, Lvzhou Li, Xinxin Li, Xin Hou, Jingbo Fang, Jingyang Li, Yonggang Meng, Liran Ma, Yu Tian
Summary: This study demonstrates a method based on stereo vision to measure three-dimensional traction stress with high spatial and temporal resolution. The method can be applied in various fields such as biology, physics, and robotics, and has important implications for related applications.
Article
Geosciences, Multidisciplinary
N. J. Finnegan, E. E. Brodsky, H. M. Savage, A. L. Nereson, C. R. Murphy
Summary: This study reveals that displacement of an active slow landslide is mainly accommodated through mm-scale stick-slip events, and the frequency of these events is related to landslide velocity and pore fluid pressure. This observation suggests similarities between slow slip in landslides and episodic slow slip along faults.
GEOPHYSICAL RESEARCH LETTERS
(2022)
Review
Physics, Mathematical
Ettore Minguzzi
REVIEWS IN MATHEMATICAL PHYSICS
(2019)
Article
Mathematics
E. Minguzzi, S. Suhr
ANNALS OF GLOBAL ANALYSIS AND GEOMETRY
(2019)
Article
Astronomy & Astrophysics
R. A. Hounnonkpe, E. Minguzzi
CLASSICAL AND QUANTUM GRAVITY
(2019)
Review
Physics, Mathematical
Ettore Minguzzi
REVIEWS IN MATHEMATICAL PHYSICS
(2020)
Article
Physics, Mathematical
E. Minguzzi
LETTERS IN MATHEMATICAL PHYSICS
(2020)
Article
Astronomy & Astrophysics
Ivan P. Costa E. Silva, Ettore Minguzzi
CLASSICAL AND QUANTUM GRAVITY
(2020)
Article
Mathematics
Yufeng Lu, Ettore Minguzzi, Shin-ichi Ohta
Summary: This research develops the theory of weighted Ricci curvature in a weighted Lorentz-Finsler framework, and extends the classical singularity theorems of general relativity. Generalized Jacobi, Riccati and Raychaudhuri equations are studied in weighted Finsler spacetimes, along with implications for the existence of conjugate points along causal geodesics. Additionally, a weighted Lorentz-Finsler version of the Bonnet-Myers theorem is shown based on a generalized Bishop inequality.
JOURNAL OF THE LONDON MATHEMATICAL SOCIETY-SECOND SERIES
(2021)
Article
Astronomy & Astrophysics
Alfonso Garcia-Parrado, Ettore Minguzzi
Summary: This paper extends the projective symmetry of the full metric-affine Einstein-Hilbert theory to a new symmetry transformation called the amplified symmetry in the space of affine connections. It proves the invariance of the Lagrangian of the standard model of particle physics under this new symmetry and shows how the gravitational Lagrangian can be modified to extend the amplified symmetry to the gravitational sector and the whole action. The resulting theory is dynamically equivalent to Einstein-Cartan's despite being genuinely metric-affine.
CLASSICAL AND QUANTUM GRAVITY
(2021)
Article
Astronomy & Astrophysics
M. Lesourd, E. Minguzzi
Summary: We prove that if a complete partial Cauchy hypersurface in a C(0) spacetime has a non-empty Cauchy horizon, the horizon is caused by almost closed causal curves behind it or by the influence of points at infinity. This result is connected to the concepts of strong cosmic censorship and Wald's conjecture, which can be formulated as a partial differential equation problem regarding the positioning of Cauchy horizons inside black hole interiors.
CLASSICAL AND QUANTUM GRAVITY
(2022)
Article
Astronomy & Astrophysics
J. Hedicke, E. Minguzzi, B. Schinnerl, R. Steinbauer, S. Suhr
Summary: This paper discusses the pseudoconvexity properties in Lorentzian and Riemannian manifolds and their relationship in static spacetimes. An example is provided to illustrate a causally continuous and maximal null pseudoconvex spacetime that is not causally simple, along with its Riemannian factor that exhibits similar characteristics.
CLASSICAL AND QUANTUM GRAVITY
(2021)
Article
Physics, Mathematical
Sebastian Gurriaran, Ettore Minguzzi
Summary: We prove that any non-degenerate smooth compact totally geodesic horizon, under the dominant energy condition, admits a smooth tangent vector field of constant non-zero surface gravity. This generalizes previous work by Isenberg and Moncrief, as well as by Bustamante and Reiris, to the non-vacuum case. Additionally, we show that any such achronal non-degenerate horizon is actually a Cauchy horizon bounded on one side by a chronology violating region.
COMMUNICATIONS IN MATHEMATICAL PHYSICS
(2022)
Article
Physics, Mathematical
E. Minguzzi
Summary: This article introduces a method for obtaining the stress-energy tensor of a perfect fluid by adding a suitable term to the Einstein-Hilbert action. This term has the physical interpretation of pressure, and its variation should be understood with respect to the metric. Velocity potentials are not required in this derivation.
INTERNATIONAL JOURNAL OF GEOMETRIC METHODS IN MODERN PHYSICS
(2023)
Article
Astronomy & Astrophysics
A. Garcia-Parrado, E. Minguzzi
Summary: We propose an action integral for Finsler gravity by pulling back an Einstein-Cartan-like Lagrangian from the tangent bundle to the base manifold. The vacuum equations, which are obtained by imposing stationarity with respect to any observer, are independent of the observer and well-defined. These equations imply that in vacuum, the metric is actually independent of the velocity variable, leading to a dynamics that coincides with that of general relativity.
GENERAL RELATIVITY AND GRAVITATION
(2022)
Article
Mathematics
Yufeng Lu, Ettore Minguzzi, Shin-ichi Ohta
Summary: In this study, we establish the Bonnet-Myers theorem, Laplacian comparison theorem, and Bishop-Gromov volume comparison theorem for weighted Finsler manifolds and weighted Finsler spacetimes with weighted Ricci curvature bounded below using the weight function. These comparison theorems are formulated with the introduction of epsilon-range, providing a natural viewpoint for interpolating weighted Ricci curvature conditions of different effective dimensions. Some of our results are new even for weighted Riemannian manifolds and generalize the comparison theorems of Wylie-Yeroshkin and Kuwae-Li.
ANALYSIS AND GEOMETRY IN METRIC SPACES
(2022)
Proceedings Paper
Mechanics
D. Canarutto, E. Minguzzi
9TH INTERNATIONAL WORKSHOP DICE2018: SPACETIME - MATTER - QUANTUM MECHANICS
(2019)
