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electroadhesion of rough surfaces, with application to touch screen technology

Just submitted a paper on electroadhesion of rough surfaces, greatly simplifying the recent theory of the great Bo Persson , with hot application to touch screens :  see here

Comments welcome.

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The false myth of the rise in Italian self-citations, and the impressively positive effect of bibliometric evaluations on the increase of the impact of Italian research

Title: The false myth of the rise in self-citations, and the impressively positive effect of bibliometric evaluations on the increase of the impact of Italian research

Authors: Pietro D'Antuono and Michele Ciavarella

Categories: physics.soc-ph math.ST stat.TH   Comments: 20 pages, 8 figures, 10 tables, in English and inItalian  License: http://arxiv.org/licenses/nonexclusive-distrib/1.0/

 https://arxiv.org/abs/1910.02948

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Mean stress effect on Gaßner curves interpreted as shifted Wöhler curves

A criterion for the mean stress effect correction in the shift factor approach for variable amplitude life prediction is presented for both smooth and notched specimens. The criterion is applied to the simple idea proposed by the authors in a previous note that Gaßner curves can be interpreted as shifted Wöhler curves. The mean stress correction used has been proposed by Smith, Watson and Topper and, more in general, by Walker.

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On the top 100 000 scientists in the world / the most authoritative and impressive ranking available today

See this impressive ranking of the top 100 000 scientists in the world.

 

Somebody told me about it as I appear as the best of my University, Politecnico di Bari in Italy.

https://journals.plos.org/plosbiology/article?id=10.1371/journal.pbio.30...

 

 

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Nick Spencer ETH wins 2018 tribology gold medal

My sincere congatulations to prof Nick Spencer for a well deserved achievement.   A lifelong dedication to many important problems of tribology, the creation of a world class lab, and editing of an important journal (Trib Lett) are just a few of many achievements of Nick.    see here.  

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Universal features in "stickiness" criteria for soft adhesion with rough surfaces

A very interesting recent paper by Dalvi et al. has demonstrated convincingly with adhesion experiments of a soft material with a hard rough material that the simple energy idea of Persson and Tosatti works reasonably well, namely the reduction in apparent work of adhesion is equal to the energy required to achieve conformal contact. We demonstrate here that, in terms of a stickiness criterion, this is extremely close to a criterion we derive from BAM (Bearing Area Model) of Ciavarella, and not very far from that of Violano et al.

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On the application of fracture mechanics mixed-mode models of sliding with friction and adhesion --- the Menga, Carbone & Dini paradox

I attach a PREPRINT of a paper on the Menga, Carbone & Dini paradox (published in JMPS last year, available at https://arxiv.org/pdf/1710.06506.pdf), that is on the application of thermodynamics to mixed mode fracture mechanics models of contacts with friction and adhesion, and an apparent paradox which emerges from this treatment.  Comments welcome.   

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A comment on "A dimensionless measure for adhesion and effects of the range of adhesion in contacts of nominally flat surfaces" by M. H. Muser

I attach a Letter I sent to the Editor of a tribology journal, concerning adhesion of rough surfaces. 

I contend that some "criteria" that have been proposed based on extrapolation of numerical results are due to the limitations in present numerical sophisticated rough contact simulations, which only span at most 3 orders of magnitude of wavelengths, so typically people simulate from nanometer to micrometer scale.

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15 phd positions in MECHANICAL ENGINEERING at Politecnico di BARI

For infos about projects in contact mechanics, friction, wear, thermoelastic instabilities (for some ideas https://www.researchgate.net/profile/Michele_Ciavarella2), please contact me at mciava@poliba.it

Deadline for application Sept.6, 2019.

Details on admission at:

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review paper: The role of adhesion in contact mechanics

Journal of The Royal Society Interface 16(151), February 2019.    DOI: 10.1098/rsif.2018.0738

Michele Ciavarella Junki Joe Junki Joe Antonio Papangelo James Richard Barber

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Is Tribology Approaching Its Golden Age? Grand Challenges in Engineering Education and Tribological Research

An interesting paper by VL Popov which suggests many problems of tribology are still very far from being remotely solved.  Despite the very detailed theories for example on rough contact using fractal surfaces on which we have debated mainly academically , there is not a single theory for any quantitative prediction of friction coefficient which can vary by 1 order of magnitude and its dependence on many variables, let alone wear coefficient which can vary up to 7 orders of magnitude.  What is left to do, other than measure?   Is tribology bound to be in practice just an experimental area? 

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On stickiness criteria for multiscale random rough contacts

We have just submitted a paper which solves a problem that I have been struggling to solve for many years.

Any comments are welcome to improve, while the paper goes the standard review process in the journal we submitted it.

 

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are fractal surfaces adhesive? a new attempt on JMPS

In 2007 I wrote a question in Imechanica, IS THERE NO PULL-OFF FOR ADHESIVE FRACTAL SURFACES?

Clearly, in 2007 this question was too hard to answer.  I pointed there that Fuller and Tabor 1975 asperity theory predicted a weird limit for a true fractal surface, that of no stickiness for any fractal dimension or amplitude, in the limit.

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a new book "Contact Mechanics" from JR Barber

I am pleased to suggest a very interesting new book from prof JR Barber of UMich, a leading scientist in the field of contact mechanics.

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Knowing the strength of adhesion

Knowing the strength of adhesion

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National TV program on Politecnico di BARI and its successes

See a national broadcast on Politecnico di BARI and the region Puglia, with its successes, including the worldwide success of Diesel common rail technology, the GE centre on Addittive Manufacturing and Cold Spray, and others.

 

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