Article
Engineering, Mechanical
Brunero Cappella, Manuel Reichelt
Summary: Wear test results often show large scattering, affecting repeatability, reproducibility, and reliability, requiring big datasets for understanding and characterizing statistical distributions. Studies have found wear coefficients to follow lognormal distributions, possibly influenced by two normally distributed variables, and may exhibit lognormal distribution when wear coefficients are not constant.
TRIBOLOGY INTERNATIONAL
(2021)
Article
Engineering, Mechanical
Jinxuan Zhu, Ramin Aghababaei
Summary: In this study, size effects in the scratch behavior of single crystalline copper were investigated using mechanism-based strain gradient crystal plasticity. The simulations showed strong size effects in the scratch hardness value and pile-up magnitude, which varied significantly and oppositely by the scratch direction. It was also demonstrated that scratch hardness, which considers both the size effect and crystallographic direction dependence, is an appropriate material property for wear characterization.
TRIBOLOGY INTERNATIONAL
(2023)
Article
Engineering, Mechanical
Ramin Aghababaei, Kai Zhao
Summary: Research has shown that a linear wear relation can be recovered only when material removal progresses by plastic deformation at the asperity tip. However, this linearity breaks down when cleavage cracking dominates the material removal.
Article
Biophysics
G. Fekete
Summary: A new hybrid wear model is introduced in this study to simulate the wear distribution between the lateral and medial side of any commercially available total knee replacements (TKRs). The main goal is to evaluate the wear properties of TKRs and predict whether they can maintain a balanced wear propagation on both tibial compartments in the long term.
JOURNAL OF MECHANICS IN MEDICINE AND BIOLOGY
(2023)
Article
Chemistry, Multidisciplinary
Sung-Je Lee, Jang-Hyun Lee, Se-Yun Hwang
Summary: This study presents a numerical analysis procedure using the discrete element method (DEM) to predict wear damage in metallic materials. The results show that wear amount can be efficiently predicted by converting long-term load into an equivalent material constant. However, the inaccuracy of previous numerical models was found to be due to the inability to consider environmental factors and particle behavior.
APPLIED SCIENCES-BASEL
(2022)
Article
Engineering, Mechanical
Valentin L. Popov, Qiang Li, Iakov A. Lyashenko, Roman Pohrt
Summary: This paper focuses on analyzing adhesive contacts under tangential motion, addressing the phenomenon of unstable movement of the contact boundary and its relation to surface roughness. It discusses how friction due to adhesion instabilities affects energy dissipation and effective works of adhesion. The study considers contributions to friction from boundary lines and contact area, with simulations and experiments showing different behaviors in small, smooth contacts versus large soft contacts.
Article
Materials Science, Multidisciplinary
Ramin Aghababaei, Emily E. Brodsky, Jean-Francois Molinari, Srinivasan Chandrasekar
Summary: This article reviews recent advances in understanding the origins of roughness on natural and engineered surfaces and their connection with subsurface deformation mechanisms. Directions for future research are discussed.
Article
Engineering, Mechanical
Krishnamurti Singh, Anirban Mahato, Mayank Tiwari
Summary: The transition from mixed stick-slip to gross-slip regime in advanced materials such as Zircaloy-4/Inconel-600, Ti6Al-4V/Inconel-600, and 9Cr-1Mo-steel/Ti-6Al-4V was explored in this study. Characterizations of worn surfaces showed sequential changes in contact state and associated chemical changes. Secondary cracks caused by low cycle fatigue in the plate material led to the movement of the stick-slip boundary and eventual transition of regimes over time.
TRIBOLOGY INTERNATIONAL
(2022)
Article
Engineering, Mechanical
I. M. Klebanov, A. M. Brazhnikova, K. A. Polyakov
Summary: This study aims to develop effective methods for calculating the wear rate of contact surfaces in rib-roller end interaction of roller bearings. Based on Archard's law, a direct step-by-step calculation method for wear rate is developed, as well as a method using averaged parameters. These two methods are used to calculate wear rates for a double-row tapered roller bearing, and it is found that a toroidal concave rib surface can reduce the wear rate up to three times compared to a tapered surface.
JOURNAL OF FRICTION AND WEAR
(2022)
Article
Chemistry, Multidisciplinary
Jianqiao Hu, Qinglei Zeng
Summary: In this paper, the effects of interfacial adhesion and material plasticity on friction and wear were studied using virtual materials through scratching experiments. The results showed that in shallow contact, both friction coefficient and wear rate increased as adhesion increased, while in deep contact, the variations were limited. Additionally, weak and strong interfacial adhesions exhibited different dependencies in friction coefficient with scratch depth, whereas wear rate increased with scratch depth. Moreover, increasing material hardness resulted in decreased friction coefficient and wear rate in both shallow and deep contacts.
Review
Chemistry, Physical
Haibo Zhang, Roman Goltsberg, Izhak Etsion
Summary: This paper reviews the classic work on wear modeling and provides a comprehensive summary of adhesive wear numerical models and techniques based on physical parameters. It investigates wear mechanisms at both the asperity level and rough surfaces, and suggests future work on considering more realistic geometries and material properties for adhesive wear modeling.
Article
Engineering, Mechanical
Jianqiao Hu, Hengxu Song, Stefan Sandfeld, Xiaoming Liu, Yueguang Wei
Summary: The Archard wear law, widely used to measure material wear, is derived from an idealized asperity flattening model, which cannot accurately represent the real situation with general interlocked asperities. Through molecular dynamics simulations, we found that the Archard law breaks down when fracture dominates the wear, and increasing interfacial adhesion or decreasing material ductility changes the dominant wear factor. We proposed a criterion to determine when the Archard wear law will fail and discussed its applicability to real materials.
TRIBOLOGY INTERNATIONAL
(2022)
Article
Metallurgy & Metallurgical Engineering
Ashish Saurabh, Kartik Joshi, Piyush Chandra Verma
Summary: Ceramic brake pads are the most advanced brake pad technology with high quality, effectiveness, and longevity. This study compares the friction and wear properties of ceramic and copper-free semi-metallic brake materials using FEM simulation and wear tests. The results show that ceramic brake material has lower wear and coefficient of friction (CoF) compared to semi-metallic material. Both materials exhibit abrasive wear as the dominant wear mechanism under high loading conditions. At 60 N load, ceramic material outperforms semi-metallic in terms of wear. The simulation and experiment results are consistent and in agreement.
TRANSACTIONS OF THE INDIAN INSTITUTE OF METALS
(2023)
Article
Engineering, Mechanical
Jianqiao Hu, Xiaoming Liu, Yueguang Wei
Summary: In particle collisions at the micro size level, adhesion becomes more important as the particle size decreases, while increased surface effects cause particles to prefer aggregation. On the other hand, as the impact velocity increases, particles tend to separate due to larger elastic repulsive interactions. Another factor that cannot be ignored during the collision of metal microparticles is dislocation plasticity, which exhibits rate and size effects. Taking into account nano-plasticity behavior, molecular simulations in this study revealed two critical impact velocities for the transition from particle separation to aggregation, which were quantified by proposed analytical models. The low critical velocity for particle aggregation is dominated by adhesion, while the high critical velocity for aggregation is dominated by dislocation plasticity, where the dislocation density in the particle after the collision is proportional to the impact velocity. With these findings, an analytical model was proposed to determine the critical particle size, below which no separation will be found regardless of the impact velocity. This critical size is proportional to the ratio of surface energy to stacking fault energy.
INTERNATIONAL JOURNAL OF IMPACT ENGINEERING
(2023)
Article
Nanoscience & Nanotechnology
Mostafa Olfat, Erfan Kadivar
Summary: This paper investigates the active sorting of particles in a dielectrophoresis microfluidic channel using the boundary element method and point-particle approach. The dynamics of particle sorting for different parameters are studied, and three different sorting regimes are observed. The results of both numerical approaches show good agreement.
MICROFLUIDICS AND NANOFLUIDICS
(2023)
Article
Multidisciplinary Sciences
Valentin L. Popov
Summary: This study presents an approximate solution for contact problems of profiles that deviate slightly from axial symmetry. The solution is derived through Betti's reciprocity theorem and validated through comparisons with other analytical and numerical solutions. The solution provides insights into the force-indentation relationship, the size and shape of the contact area, and the pressure distribution. Additionally, the study generalizes the Method of Dimensionality Reduction to non-axisymmetric profiles.
Article
Mechanics
Qiang Li, Josefine Wilhayn, Iakov A. Lyashenko, Valentin L. Popov
Summary: We numerically study adhesive contact between an elastic half-space and a rigid punch with elliptic shape and superimposed roughness. The main governing parameter of different adhesion modes is the Johnson parameter. The adhesive force increases with the normal force during compression until it reaches a plateau. The evolution of the contact area during pull-off depends on the roughness and pre-loading. Experimental results differ from numerical simulation and analytical theory.
MECHANICS RESEARCH COMMUNICATIONS
(2022)
Article
Materials Science, Ceramics
Xu Wang, Valentin L. Popov, Zhanjiang Yu, Yiquan Li, Jinkai Xu, Qiang Li, Huadong Yu
Summary: The cutting performance of textured polycrystalline diamond tools on SiCp/Al composites was studied and it was found that texture parameters play a significant role in machining. Textured tools reduce cutting force and tool wear, improve surface quality, and change the chip flow direction. The cutting mechanism of textured tools was elucidated through numerical simulation.
CERAMICS INTERNATIONAL
(2022)
Article
Mechanics
I Argatov, L. Voll, V. L. Popov
Summary: This study investigates the steady-state dynamic response of a single-degree-of-freedom system with both a hysteretic element and a spring. It uses the Hertz-Cattaneo-Mindlin theoretical framework and the Masing hysteresis model to describe the hysteretic behavior of multiple localized frictional contact interfaces. The steady-state tangential displacement amplitude of a rigid body under harmonic tangential force excitation is approximately determined using the equivalent linearization technique, with a focus on evaluating frictional damping and determining the backbone curve of the Masing model.
Article
Physics, Applied
I. A. Lyashenko, V. L. Popov
Summary: The contact between a cylindrical steel indenter and an elastomer with high adhesive properties has been investigated. Good agreement between computer simulation and experimental data was obtained for the indentation and detachment processes in the normal direction. The adhesive component of the friction force in the rolling-friction regime was determined by analyzing the relationship between the tangential component of the contact force and wheel displacement. The presence of adhesion was found to affect sliding friction, with the force being proportional to the contact area.
Article
Chemistry, Analytical
Xu Wang, Valentin L. Popov, Zhanjiang Yu, Yiquan Li, Jinkai Xu, Qiang Li, Huadong Yu
Summary: This study investigates the cutting performance improvement of PCD tools by preparing micro-pit textures on their surfaces using a nanosecond laser. The textured tools showed a significant reduction in cutting force, tool wear, and surface adhesion. In addition, the textured tool also provided better chip transfer and anti-tipping during micro-turning experiments.
Article
Multidisciplinary Sciences
Alexander E. Filippov, Valentin L. Popov
Summary: This article presents the application of cylindrical and spherical symmetries in numerical studies of many-body problems. The use of periodic boundary conditions with cylindrical symmetry is shown to effectively reduce the influence of boundary conditions and obtain reasonably accurate results. A physically realizable cylindrical configuration is also explored. The advantages and disadvantages of symmetric realizations are discussed. Furthermore, the article investigates the use of spherical symmetry, which eliminates boundaries in a three-dimensional system. Using tectonic dynamics as an example, interesting patterns resembling real structures are found, emphasizing the potential role of perturbations in the planet's axis of rotation in their formation.
Article
Chemistry, Analytical
Iakov A. Lyashenko, Valentin L. Popov, Roman Pohrt, Vadym Borysiuk
Summary: In this study, we present the design of a high-precision tribometer laboratory setup. The entire design process is described, starting from concept development to the creation of an accurate 3D model and final assembly of functional parts. The setup is based on a previously designed device, with modifications made to address its limitations. An example is provided to demonstrate data processing and correction for backlash and signal drift errors. The flexibility of the equipment is highlighted, as peripheral parts can be modified without changing the main frame.
Article
Physics, Multidisciplinary
I. I. Argatov, I. A. Lyashenko, V. L. Popov
Summary: This study analyzes the non-quasistatic detachment of a flat-ended cylindrical punch from an adhesive rubber layer using recent experimental data. The work of adhesion is assumed to depend on the velocity of the contact area contour according to the Gent-Schultz model. The evolution of the contact radius as a function of punch displacement is described by a first-order ordinary differential equation, which exhibits nonzero detachment. An analytically approximate solution is proposed to fit the model to experimental force-displacement curves, and a parametric analysis of the rubber layer as an elastic half-space is presented.
Article
Chemistry, Analytical
Vadym Borysiuk, Iakov A. Lyashenko, Valentin L. Popov
Summary: Thermal stability of triple layered Au@Pt@Au core-shell nanoparticles for H2O2 bi-directional sensing was investigated through computational study. The raspberry-like shape of the nanoparticles and their structural parameters were studied using classical molecular dynamics simulations. The results showed that the core-shell structure of the nanoparticles was maintained up to approximately 900 K, but was destroyed at higher temperatures.
Article
Engineering, Electrical & Electronic
Iakov A. Lyashenko, Alexander E. Filippov, Valentin L. Popov
Summary: This experimental study investigates the friction process between a steel spherical indenter and a soft elastic elastomer with strong adhesive interaction. The tangential stress in the contact area remains constant during uni-lateral continuous sliding, regardless of indentation depth and loading details. A simple numerical model is proposed, treating the elastic substrate as a two-dimensional elastic layer with in-plane elastic interactions. This model qualitatively reproduces the observed behavior of the system.
Article
Engineering, Mechanical
Iakov A. A. Lyashenko, Valentin L. L. Popov, Vadym Borysiuk
Summary: This paper reviews the analytical, numerical, and experimental approaches used to describe the mechanical contact between a rigid indenter and an elastic half-space coated with an elastic layer. Numerical simulations were conducted using the generalized boundary element method, and the results were verified using an analytical approximation. Additionally, experimental studies were performed to investigate adhesive contacts between hard indenters and soft rubber layers. The comparison of results from these three methods demonstrates good agreement, supporting the developed simulation technique for small range adhesive forces.
Article
Engineering, Electrical & Electronic
Henning Burger, Fabian Forsbach, Valentin L. Popov
Summary: The article presents a formulation of the BEM for simulating tangential contact with an elastic half-space coated with an elastic layer of different properties. The BEM formulation used a fast Fourier-transform method, with the fundamental solution determined directly in Fourier space. Numerical tests were conducted and validated against analytical solutions for thin and thick layers, as well as finite thickness layers using FEM calculations.
Article
Engineering, Multidisciplinary
Iakov A. Lyashenko, Valentin L. Popov, Vadym Borysiuk
Summary: This study investigates the process of indentation and detachment of a steel indenter in a soft elastomer layer under different inclination angles. Experimental and theoretical analysis reveals the differences in characteristics between small indentation angles and angles close to the normal angle.