friction
Leonardo's universal friction coefficient is found to be universal after all!
It turns out that friction coefficient 0.25 suggested as universal by Leonardo da Vinci more than 500 years ago has some universaility, as minimum friction coefficient for any granular material: it makes me proud as italian ;)
I guess it would be interesting to show this experimental result also theoretically or numerically, any interest?
On friction effects and the conditions of failure of adhesion in punch shaped pillars and mushrooms
Considerable research has been conducted on shape of pillar ends for optimal adhesion. In experiments with elastomers it has been found that mushrooms-ended ones are superior to flat-ended ones, but early experiments have suggested an extremely strong scaling in strength with pillar radius (del Campo et al Langmuir;23 :10235-43, 2007). We discuss various theories and experimental results on scaling of strength, and in particular we elaborate recent experiments on single pillars with mushroom ends finding that the scaling on strength is much less surprising.
“Mechanics of granular materials: Modeling and characterization” MiniSymposium #0103 at EMI/PMC 2024, Chicago, IL, 2024
EMI/PMC 2024, Chicago, IL, 2024 – MiniSymposium #0103 “Mechanics of granular materials: Modeling and characterization”
apparent paradox: for a sliding flat punch on a viscoelastic halfspace, friction is zero or not?
dear Imechanica friends
here is an apparent paradox: for a sliding flat punch on a viscoelastic halfspace, friction is zero or not? Certainly there seems to be viscoelastic dissipation, but the pressure is also normal to dispacements, so am I missing something obvious here? Any help is welcome!
Thanks
Mike
Postdoc opening--Modeling Shock Compaction of Granular Materials
Colleagues,
The Solid Mechanics--Damage and Failure team at Los Alamos National Laboratory is seeking a highly motivated and productive postdoc candidate in the area of shock compaction, with a focus on simulating the microstructure evolution of granular materials using explicit representation of microstructures.
Postdoctoral Position: Oxide Nanoparticles as Lubricant Additives
THE SCHOOL OF ENGINEERING AND APPLIED SCIENCE at the UNIVERSITY OF PENNSYLVANIA invites applications for a full-time position as a Postdoctoral Researcher in the DEPARTMENT OF MECHANICAL ENGINEERING AND APPLIED MECHANICS in the laboratory of Prof. Robert W. Carpick (http://carpick.seas.upenn.edu).
Multifunctional “Hydrogel Skins” on Diverse Polymers with Arbitrary Shapes
In this paper, we introduce a new simple yet effective strategy to form "hydrogel skins" on polymer-based medical devices with arbitrary shapes. Hydrogel skins can convert any surface of polymer devices into robust, wet, soft, slippery, antifouling, and ionically conductive without affecting the original properties and geometries.
Abstract