The Experts below are selected from a list of 231 Experts worldwide ranked by ideXlab platform
Michael Nosonovsky - One of the best experts on this subject based on the ideXlab platform.
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Ultraslow Frictional sliding and the stick-slip transition
Applied Physics Letters, 2018Co-Authors: Alexander D. Breki, Michael NosonovskyAbstract:Understanding the onset of sliding is the key to understanding mechanisms of Friction as a fundamental dissipative surface phenomenon. Most recent studies of the abrupt stick-to-slip transition concentrate on either nanotribological or fracture mechanics analysis. Here, we investigate ultraslow sliding Friction, which is intermediate between the static and dynamic Friction. During ultraslow Friction, the sliding velocity is comparable with the relaxation rate of the Material. Friction between two very smooth steel samples was studied at the sliding velocity of 37 nm/s. The force-displacement dependencies suggest that the onset of sliding is a gradual transition between two regimes rather than an abrupt irreversible transition from static to kinetic Friction observed at higher sliding velocities.Understanding the onset of sliding is the key to understanding mechanisms of Friction as a fundamental dissipative surface phenomenon. Most recent studies of the abrupt stick-to-slip transition concentrate on either nanotribological or fracture mechanics analysis. Here, we investigate ultraslow sliding Friction, which is intermediate between the static and dynamic Friction. During ultraslow Friction, the sliding velocity is comparable with the relaxation rate of the Material. Friction between two very smooth steel samples was studied at the sliding velocity of 37 nm/s. The force-displacement dependencies suggest that the onset of sliding is a gradual transition between two regimes rather than an abrupt irreversible transition from static to kinetic Friction observed at higher sliding velocities.
Michael R. Lovell - One of the best experts on this subject based on the ideXlab platform.
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On the Sliding Friction Characteristics of Unidirectional Continuous FRP Composites
Journal of Tribology, 2001Co-Authors: Xinguo Ning, Michael R. LovellAbstract:By applying a closed-form analytical solution Hwu and Fan (1998) for an anisotropic half-plane, the contact characteristics of unidirectional continuous fiber-reinforced plastic (FRP) composites are investigated. The particular condition of a rigid parabolic cylinder in normal sliding contact with the composite is evaluated. The influence of FRP composite matrix Material, Friction coefficient, fiber Material, fiber orientation, and fiber volume fraction on the surface contact pressure are determined and evaluated by comparison to published experimental data and results from the finite element method. From the analytical results, several important trends for the contact characteristics of fiber-reinforced plastics are ascertained and discussed with respect to the wear and design-ability of FRP Materials.
Alfred J. Crosby - One of the best experts on this subject based on the ideXlab platform.
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Insight into the periodicity of Schallamach waves in soft Material Friction
Applied Physics Letters, 2006Co-Authors: Charles J. Rand, Alfred J. CrosbyAbstract:A dominant mechanism in Friction of soft Material interfaces is the onset and propagation of Schallamach waves. Schallamach waves are “tunnels” of air that provide relative displacement between the slider and the substrate rather than the instantaneous interfacial failure involved with stick-slip. Here, through model experiments and analysis, the authors present a fundamental relationship between the periodicity of Schallamach waves (λ) and the ratio of interfacial adhesion (Gc) over complex elastic modulus (E*). This deconvolution of bulk and interfacial contributions to the Friction of soft Materials leads to interesting predictions that will impact Material design for a wide range of applications.
Yossi Cohe - One of the best experts on this subject based on the ideXlab platform.
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effect of counterface roughness on the Friction of bionic wall shaped microstructures for gecko like attachments
Bioinspiration & Biomimetics, 2017Co-Authors: Haytam Kasem, Yossi CoheAbstract:Hairy adhesive systems involved in gecko locomotion have drawn the interest of many researchers regarding the development of bionic solutions for fast and reversible adhesive technologies. To date, despite extensive efforts to design gecko-inspired adhesive surfaces, adhesion and Friction capacities are often evaluated using smooth and rigid counterfaces, in general glass, whereas most natural and artificial surfaces inevitably have a certain level of roughness. For that reason, in this study experiments tested the effects of the substrate roughness on the Friction of bionic wale-shaped microstructures for gecko-like attachments. To this end, 12 substrates with different isotropic roughness were prepared using the same Epoxy Material. Friction force was measured under various normal loads. It was concluded that classical roughness parameters, considered separately, are not appropriate to explain roughness-related variations in Friction force. This has led us to develop a new integrative roughness parameter that combines characteristics of the surface. The parameter is capable of classifying the obtained experimental results in a readable way. An analytical model based on the experimental results has been developed to predict the variation of the Friction force as a function of counterface roughness and applied normal load.
Alexander D. Breki - One of the best experts on this subject based on the ideXlab platform.
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Ultraslow Frictional sliding and the stick-slip transition
Applied Physics Letters, 2018Co-Authors: Alexander D. Breki, Michael NosonovskyAbstract:Understanding the onset of sliding is the key to understanding mechanisms of Friction as a fundamental dissipative surface phenomenon. Most recent studies of the abrupt stick-to-slip transition concentrate on either nanotribological or fracture mechanics analysis. Here, we investigate ultraslow sliding Friction, which is intermediate between the static and dynamic Friction. During ultraslow Friction, the sliding velocity is comparable with the relaxation rate of the Material. Friction between two very smooth steel samples was studied at the sliding velocity of 37 nm/s. The force-displacement dependencies suggest that the onset of sliding is a gradual transition between two regimes rather than an abrupt irreversible transition from static to kinetic Friction observed at higher sliding velocities.Understanding the onset of sliding is the key to understanding mechanisms of Friction as a fundamental dissipative surface phenomenon. Most recent studies of the abrupt stick-to-slip transition concentrate on either nanotribological or fracture mechanics analysis. Here, we investigate ultraslow sliding Friction, which is intermediate between the static and dynamic Friction. During ultraslow Friction, the sliding velocity is comparable with the relaxation rate of the Material. Friction between two very smooth steel samples was studied at the sliding velocity of 37 nm/s. The force-displacement dependencies suggest that the onset of sliding is a gradual transition between two regimes rather than an abrupt irreversible transition from static to kinetic Friction observed at higher sliding velocities.