Article
Materials Science, Multidisciplinary
Tobias Brink, Lucas Frerot, Jean-Francois Molinari
Summary: The study proposes a simple model for adhesive wear in dry sliding conditions, which is based solely on material properties and surface parameters, without fit parameters. By explicitly tracking the sliding process, the model connects particle emission rates and sizes to the macroscopic wear rate in a meaningful way. Further controlled wear experiments and parameters from such work are needed to fully verify and enhance the model.
JOURNAL OF THE MECHANICS AND PHYSICS OF SOLIDS
(2021)
Article
Materials Science, Multidisciplinary
R. Civiero, F. Perez-Rafols, L. Nicola
Summary: The effect of a passivation layer on a rough metal surface during contact loading is studied using dislocation dynamics simulations. The metal body is modeled as an FCC single crystal with a self-affine rough surface, which can be either bare or covered by a thin coating that is impenetrable to dislocations. The simulation allows for analyzing the influence of surface roughening caused by dislocation motion, where bare surfaces result in crystallographic steps due to dislocation glide, while passivated surfaces stop dislocations at the interface.
MECHANICS OF MATERIALS
(2023)
Article
Engineering, Mechanical
Anahita Emami, Seyedmeysam Khaleghian, Saied Taheri
Summary: Modeling the real contact area is crucial in various tribological processes, and the accuracy of predicting friction, adhesion, and wear depends on it. Consideration of physical parameters such as surface roughness characteristics, material properties, sliding velocity, and normal load can lead to a more precise estimation of the friction coefficient.
Article
Chemistry, Physical
Kevin Logrande, M. Ravi Shankar, Kaushik Dayal
Summary: Liquid crystalline elastomers (LCEs) are programmable materials that respond to external stimuli, and their anisotropic response is controlled by the nematic director. This study focuses on pre-curved LCE strips and develops a one-dimensional model that accurately captures the experimental observations.
Article
Mathematics, Interdisciplinary Applications
Robert L. Jackson, Yang Xu, Swarna Saha, Kyle D. Schulze
Summary: This study uses the boundary element method to predict the real contact area of perfectly elastic rough surfaces, aiming to confirm the linear relationship between contact area, root-mean-square slope, and applied load predicted by fractal diffusion-based rough surface contact theory. However, experimental results reveal a complex response that deviates from the expected behavior. Further evaluation of the variation in root-mean-square slope and system spectrum related to contact features is needed to understand why this discrepancy occurs in some types of surfaces and not others.
FRACTAL AND FRACTIONAL
(2021)
Article
Mechanics
Sihe Wang, Weike Yuan, Xuanming Liang, Gangfeng Wang
Summary: This paper presents an analytical contact model for elastic or elastic-perfectly plastic Gaussian rough surfaces and validates it with finite element simulations. The model accurately predicts the contact behavior, showing good agreement with the simulation results. Additionally, the influence of plastic deformation on the contact response is characterized by introducing a dimensionless plasticity parameter.
EUROPEAN JOURNAL OF MECHANICS A-SOLIDS
(2022)
Article
Materials Science, Multidisciplinary
J. Joe, A. Wang, J. R. Barber
Summary: We have developed a theoretical model to predict the load-displacement relation and probability density function for gaps between contacting rough surfaces. The predictions of this theory were compared with numerical results, demonstrating good agreement.
JOURNAL OF THE MECHANICS AND PHYSICS OF SOLIDS
(2023)
Article
Mechanics
Xuan-Ming Liang, Chun-Yun Jiang, Meng-Rui Wang, Wan-lin Dai, Gang-Feng Wang
Summary: In this study, an optical apparatus is designed to accurately capture the real contact areas between rough metallic samples and flat quartz glass using the frustrated total internal reflection technique and an Otsu method. The incremental equivalent contact model developed by the researchers is employed to predict the load-area relationship, and it shows good agreement with experimentally measured results for samples of various materials and morphologies, confirming the efficiency of the model.
EUROPEAN JOURNAL OF MECHANICS A-SOLIDS
(2023)
Article
Engineering, Chemical
Joseph M. Monti, Antoine Sanner, Lars Pastewka
Summary: Understanding the distribution of interfacial separations between rough surfaces is crucial for estimating adhesive forces. By assuming non-adhesive, frictionless contact between self-affine surfaces, a power-law divergence for small gaps is derived. The characteristic length scale is determined by the product of rms surface slope and mean diameter of contacting regions, and these findings apply to weakly adhesive contacts as well, connecting to recent theories on adhesion between rough surfaces.
Article
Engineering, Chemical
De Huang, Xiang Yan, Roland Larsson, Andreas Almqvist
Summary: This paper presents a new numerical method based on the bisection algorithm and the boundary element method for accurately capturing the critical pressure of a sealing system. The results show that the critical pressure is related to the non-planar geometry of the sealing surfaces.
Article
Engineering, Chemical
Shijun Yin, Gianluca Costagliola, Jean-Francois Molinari
Summary: We investigate the persistence of micro-contacts between two elastic random rough surfaces using a simple model, finding that the original contact clusters gradually disappear and are replaced by new ones, while the real contact area remains constant. This study sheds light on the microscopic origins of phenomenological rate-and-state friction laws and memory effects observed in frictional sliding.
Article
Engineering, Mechanical
G. F. Wang, X. M. Liang, D. Yan
Summary: A new method for determining the relationship between real contact area and surface separation is proposed in this study. The model predicts a linear relationship between real contact area and load within a realistic separation range and shows good agreement with direct finite element calculations. The model is not limited to isotropic Gaussian surfaces and provides a general approach to studying the contact of rough surfaces.
JOURNAL OF TRIBOLOGY-TRANSACTIONS OF THE ASME
(2021)
Article
Biochemical Research Methods
Alejandro Torres-Sanchez, Max Kerr Winter, Guillaume Salbreux
Summary: We propose a modelling and simulation framework for cell aggregates in three dimensions based on interacting active surfaces. The framework captures cell mechanics, inter-cell forces, and the effect of adhesion molecules. We discretize the model equations using a finite element method and implement it in C++. This framework allows for the systematic exploration of the mechanics of cell aggregates at the cell to tissue-scale, which is important in the morphogenesis of embryos and organoids.
PLOS COMPUTATIONAL BIOLOGY
(2022)
Article
Multidisciplinary Sciences
Ying Zhou, Chenguang Zhang, Wenchang Zhao, Shiyu Wang, Pingan Zhu
Summary: This study demonstrates that the rebound of droplets can be effectively suppressed by incorporating bubbles into the droplets on super-repellent surfaces. The suppression arises from the counteractive capillary effects within bubble-encapsulated hollow droplets.
NATURE COMMUNICATIONS
(2023)
Article
Engineering, Mechanical
Francesc Perez-Rafols
Summary: Two-scale models are effective for studying mechanical problems with a wide range of length scales. However, they cannot be directly applied in contact mechanics due to a lack of scale separation, which results in inadequate representation of local-scale results. This work proposes a model that incorporates stochastic variability of local scale results into the global-scale problem to overcome this issue. Several test cases are conducted to demonstrate the model's performance.
TRIBOLOGY INTERNATIONAL
(2023)
Correction
Chemistry, Physical
Sergey V. Sukhomlinov, Martin H. Mueser
JOURNAL OF CHEMICAL PHYSICS
(2020)
Article
Chemistry, Physical
Sergey Sukhomlinov, Martin H. Mueser
JOURNAL OF CHEMICAL PHYSICS
(2020)
Article
Multidisciplinary Sciences
Riad Sahli, Aubin Prot, Anle Wang, Martin H. Mueser, Michal Piovarci, Piotr Didyk, Roland Bennewitz
SCIENTIFIC REPORTS
(2020)
Article
Engineering, Chemical
Anle Wang, Martin H. Mueser
Summary: In this work, the elastic contact between isotropic and anisotropic, rigid, randomly rough surfaces and linearly elastic counterfaces, as well as the subsequent Reynolds flow through the gap between them, is numerically studied. The percolation threshold is found to be dependent on fluid flow direction in anisotropic systems, and a critical contact area near 0.415 is confirmed. Effective-medium treatments provide accurate expressions for Reynolds fluid flow conductances.
Article
Chemistry, Multidisciplinary
Hongyu Gao, James P. Ewen, Remco Hartkamp, Martin H. Mueser, Daniele Dini
Summary: The study investigates the kinetic friction performance of organic friction modifiers (OFMs) at a nanoscale using nonequilibrium molecular dynamics simulations. By studying the coverage of stearamide OFMs, the research reveals that the friction coefficient and indentation depth exhibit nonmonotonic relationships at different coverages.
Article
Engineering, Chemical
Martin H. Mueser
Summary: The study found an approximately linear relationship between the relative contact area ar and pressure p above the critical dimension, and the pressure dependence of the mean gap ug showed identical trends in each studied case.
Editorial Material
Engineering, Chemical
Martin H. Mueser
Article
Engineering, Chemical
Sergey V. Sukhomlinov, Martin H. Mueser
Summary: Through density-functional theory simulations, it was found that initially disconnected zinc phosphate molecules undergo hybridization changes in response to externally imposed deformations, resulting in the formation of rigid networks. Stress anisotropy reduces the pressure required for network formation, while networks formed under isotropic deformations are stiffer, more isotropic, and lower in energy after decompression. Stress-memory effects were found to be encoded in the arrangement of atoms in the second neighbor shell of the zinc atoms.
Article
Materials Science, Multidisciplinary
Hongyu Gao, Tobias P. W. Menzel, Martin H. Mueser, Debashish Mukherji
Summary: In this study, the prediction of specific heat is corrected for quantum effects using an analysis of the mass-weighted velocity autocorrelation function, leading to agreement with experimental data. Corrections for both all-atom and united-atom descriptions of chain molecules are outlined, and deviations between computed corrections and experimental values are found to be small.
PHYSICAL REVIEW MATERIALS
(2021)
Article
Physics, Multidisciplinary
Martin H. Mueser, Bo N. J. Persson
Summary: This article presents simulations on the sticking contact between a rigid cylinder and a viscoelastic half space, revealing a maximum in the work of separation at intermediate pull-off velocities. The maximum tensile forces increase monotonically with the pull-off speed and the crack tip speed, consistent with the Persson-Brener approach. Additionally, the fracture mode transitions from interfacial crack propagation to quasi-uniform bond breaking with an increasing range of adhesion.
Article
Engineering, Chemical
Sergey V. Sukhomlinov, Guido Kickelbick, Martin H. Mueser
Summary: Using molecular dynamics simulations based on density-functional theory, this study investigates stress and temperature-induced chemical reactions in systems containing triphosphoric acid and zinc phosphate molecules. The findings reveal that the nature of the products depends on the applied conditions, with isotropic and shear stress leading to different (zwitter-) ionic products. Thermal cycles also generate free ions, but these reactions are endothermic instead of exothermic like stress-induced transitions. The study also shows that before zinc atoms change their coordination under stress, proton mobility increases, and the hydrostatic stress required for this process is reduced with increasing shear. These findings have implications for understanding the impact of stress on material properties.
Article
Materials Science, Multidisciplinary
Christian Mueller, Manar Samri, Rene Hensel, Eduard Arzt, Martin H. Mueser
Summary: Viscoelasticity and small-scale, elastic multistability are two mechanisms that contribute to adhesion hysteresis. This study compares the simulated and experimental results of the interfacial force and contact area evolution between a soft elastomer and a rigid punch with roughness. The findings reveal that hysteresis is enhanced when the topography's saddle points come into contact, but is impeded by viscoelastic forces and may require large preloads. This coaction of viscous and multistability effects is relevant to macroscopic polymer contacts and adhesive gripping devices.
JOURNAL OF THE MECHANICS AND PHYSICS OF SOLIDS
(2023)
Article
Physics, Multidisciplinary
Christian Mueller, Martin H. Mueser, Giuseppe Carbone, Nicola Menga
Summary: This study investigates the impact of the coupling of normal and in-plane elastic response on the tribological properties when Hertzian or randomly rough indenters slide past an elastic body. The study finds that compressibility-induced coupling increases maximum tensile stresses and decreases friction, violating Amontons' law macroscopically.
PHYSICAL REVIEW LETTERS
(2023)
Article
Engineering, Mechanical
Anle Wang, Yunong Zhou, Martin H. Mueser
Summary: This study quantitatively analyzes the energy loss phenomenon during contact between rigid indenters and adhesive surfaces, with a focus on the design of cohesive-zone models for efficient simulation of dynamic processes.
Article
Engineering, Mechanical
Martin H. Mueser