A5003985920- Adhesion, Friction, and Surface Interactions
- Mechanical stress and fatigue analysis
- Force Microscopy Techniques and Applications
- Gear and Bearing Dynamics Analysis
- Tribology and Lubrication Engineering
- Brake Systems and Friction Analysis
- Fatigue and fracture mechanics
- Surface Roughness and Optical Measurements
- Tribology and Wear Analysis
- Railway Engineering and Dynamics
- Mechanical Behavior of Composites
- Probabilistic and Robust Engineering Design
- Vibration and Dynamic Analysis
- Metal and Thin Film Mechanics
- Contact Mechanics and Variational Inequalities
- Electrical Contact Performance and Analysis
- Surface Modification and Superhydrophobicity
- Numerical methods in engineering
- Bladed Disk Vibration Dynamics
- Structural Load-Bearing Analysis
- Elasticity and Material Modeling
- Engineering Structural Analysis Methods
- Material Properties and Failure Mechanisms
- Rheology and Fluid Dynamics Studies
- Advanced machining processes and optimization
Universität Hamburg
2013-2025
Hamburg University of Technology
2013-2025
Polytechnic University of Bari
2015-2024
Czech Technical University in Prague
2018
Instituto Politécnico Nacional
2003-2015
Google (United States)
2015
Construction Technologies Institute
2003-2008
Novartis (Ireland)
2003
National Academies of Sciences, Engineering, and Medicine
2001
University of Oxford
1998-2000
Adhesive (e.g. van der Waals) forces were not generally taken into account in contact mechanics until 1971, when Johnson, Kendall and Roberts (JKR) generalized Hertz' solution for an elastic sphere using energetic argument which we now recognize to be analogous that used linear fracture mechanics. A significant result is the load-displacement relation exhibits instabilities approaching bodies 'jump in' contact, whereas separated out' at a tensile 'pull-off force'. The JKR approach has since...
A contact problem is considered in which an elastic half–plane pressed against a rigid fractally rough surface, whose profile defined by Weierstrass series. It shown that no applied mean pressure sufficiently large to ensure full and indeed there are not even any areas of finite dimension — the area consists set fractal character for all values geometric loading parameters.A solution partial sinusoidal surface used develop relation between distribution at scale n − 1 n. Recursive numerical...
The problem of the detachment a flat indenter from plane adhesive viscoelastic strip thickness "b" is studied. For any given retraction speed, three different regimes are found: (i) for very small stress constant and equal to theoretical strength interface, (ii) intermediate values decays approximately as b−1/2, (iii) thick layers obtained corresponding case punch detaching halfplane. By using boundary element method comprehensive numerical study performed which assumes linear material with...
We solve numerically the problem of a sliding viscoelastic cylinder in presence adhesion, modelled using Lennard Jones force-separation law. For material, linear standard model is considered. show entire problem, and friction coefficient particular, depends on four dimensionless quantities: Maugis-Tabor parameter λ, load W, speed V, ratio between relaxed instantaneous modulus k=E0/E∞. small which corresponds to rather rigid cylinders, returns classical Hunter solution for large compressive...
Abstract In classical experiments, it has been found that a rigid cylinder can roll both on and under an inclined rubber plane with friction force depends power law of velocity, independent the sign normal force. Further, contact area increases significantly velocity related law. We try to model qualitatively these experiments numerical boundary element solution standard linear solid we find for sufficiently large Maugis–Tabor parameter $$\lambda$$ <mml:math...
The contact problem and stress state for indentation by a flat punch with rounded edges is studied. For the itself analytical solutions are obtained both surface pressure interior fields. Cases of normal frictional contact, latter in sliding or partial slip conditions, all treated. transition from Hertzian configuration to between nominally pad contacting discussed, it found that strength decays surprisingly slowly. Regarding von Mises yield parameter, there range configurations which...
True contact between randomly rough solids consists of myriad individual microjunctions. While their total area controls the adhesive friction force interface, other macroscopic features, including viscoelastic friction, wear, stiffness, and electric resistance, also strongly depend on size shape We show that, in elastomer contacts, microjunctions significantly varies as a function shear applied to interface. This process leads growth anisotropy overall which saturates sliding regime. that...
Abstract We show that the detachment of a flat punch from viscoelastic substrate has relatively simple behaviour, framed between Kendall’s elastic solution at relaxed modulus and instantaneous modulus, cohesive strength limit. find hardly any dependence pull-off force on details loading process, including maximum indentation preload rate, resulting much simpler than case spherical punch. Pull-off peaks highest speeds unloading, when energy dissipation is negligible, which seems to be in...
The contact between a rigid Hertzian indenter and an adhesive broad-band viscoelastic substrate is considered. material behaviour described by modified power law model, which characterized only four parameters, the glassy rubbery elastic moduli, characteristic exponent n timescale τ0. maximum adherence force that can be reached while unloading from relaxed half-space studied means of numerical implementation based on boundary element method, as function velocity, preload varying broadness...