Mike Ciavarella's blog

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a JKR theory of adhesion for anisotropic solids

Jim Barber and I just got accepted this paper in JMPS, and it is also already available on Arxiv.  We found a remarkably simple closed form solution for adhesion on orthotropic materials in the planes of symmetry.  This shows adhesion can increase significantly due to anisotropy, namely the JKR solution continues to hold in the sense of mean elastic modulus, but the prefactor can grow without limit. We expect applications in crystals indentation, but also in locomotion in biological world.

 

http://arxiv.org/abs/1312.2779


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How safe are metal-on-metal hip implants? and are ceramic-on-ceramic safer? Or we will discover soon they are not?

Would you believe this story?

To me, that metal - on - metal had large friction, especially with the newest designs, it was clear from the old Sir Charnley studies in Leeds in 1950s published in his gold book. 

Anyway, when I looked at ceramic on ceramic joints, I also found evidence of increased friction.  Maybe ceramic debris is less toxic?

Please comment.  What can we do outside USA to improve the situation?

Michele Ciavarella 


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1st International IEEE Workshop on Metrology for Aerospace. Benevento, Italy, May, 29-30, 2014.

Dear Colleagues and Friends,

We are pleased to invite you to contribute to the 1st International IEEE Workshop on Metrology for Aerospace. 

The event is co-technical sponsored by two IEEE Societies, AESS and IMS. 
The event includes but is not limited to new technology for metrology-assisted production in aerospace industry, aircraft component measurement, sensors and associated signal conditioning for aerospace, calibration methods for electronic test and measurement for aerospace.


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Is wear law really Archard's law (1953), or Reye's law (1860) ???

In 1860 the mathematician and geometer Reye proposed a simple and elegant theory for explaining the consumption of a solid body when it slides with friction on a rough surface [8]. Reye’s model became very popular in Europe (in Italy was promulgated by Panetti [7]), and it is still taught in university courses of applied mechanics. But, strangely enough, this theory has been totally ignored in English and American literature.  Why? A paper from 2001 by Villaggio is interesting to read today.


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megagrants in russia! who whould join me in preparing one application?

Dear colleagues!


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International Workshop and School  New Methods of Numerical Simulation and Measurement in Tribology Sandanski, Bulgaria, October

Dear Mechanician

 

please find enclosed the announcement of the Workshop in Sandanski.

One can find it also on the cite:http://wp1119223.server-he.de/Sandanski2013.html

Please fill the registration form (enclosed)

 


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URGENT: phd position in the group of Prof Bigoni (Trento, Italy) with possible sharing with us in PoliBA

 

I received this letter from Prof Davide Bigoni

 
Marie Curie PhD position at University of Trento (Italy): deadline September 15

 
It is a top opportunity in Italy, the leading group in Italy in elasticity, plasticity and nonlinear elasticity. A very active university and town. 

I expect many applications.

 prof. MC


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I HAVE A REGIONAL UNIVERSITY DREAM --- a speech to the candidates to Rector of Politecnico di BARI

 taken from http://rettorevirtuoso.blogspot.com/2013/07/i-have-regional-university-d...

 Sorry for the spell check --- I did not have time to do it!

 

I HAVE A REGIONAL UNIVERSITY DREAM


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Wear-out models for composite materials fatigue, and the "strange case" of Kassapoglou's "too good to be true" model

Wear-out models have been very successful for fitting probabilistic SN
curves of composite materials.  The "strength-life equal rank
assumption"
wear-out models for fatigue of composite materials were
first presented by Hahn and Kim [1], and later as a fitting approach to fatigue
data by Sendeckyj [2].


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sad news for mechanician. Departure of HD Bui, member of french academy of science

Unfortunately, HD Bui, 76, passed away yesterday evening. An elegant, dedicated, very discreet but bright mind, HD Bui made a long career at Ecole Polytechnique and EDF, making important contributions in fracture mechanics and inverse engineering.  Lately, he returned to work on his interesting contributions on the Cheops pyramid and the spiralling internal structure.

He was considered the most prominent vietnamese scientist in France, of 400 000 living there.


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suggestions about hysteresis loops in transient from lubricated to dry friction

I HAVE ADDED TWO PAGES FROM A NICE REVIEW FROM GOODMANN ON SLIP DAMPING

 


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retirement age or discrimination? Nature speaks of "sticking" around, but in europe we have new laws

In January 2011, the UK government announced its intention to stop
compulsory retirement for people aged 65, despite criticism of the move
by employers’ groups. Campaigners against age discrimination and unions
welcomed the change. However, official guidance makes it clear that
employers will be able to dimiss staff no longer capable of carrying out
their work. Official figures show more than two thirds of British
employers have already eliminated fixed retirement ages.

 http://www.eurofound.europa.eu/eiro/2011/02/articles/uk1102039i.htm


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9 PhD positions in Mechanical Engineering at Politecnico di BARI - Italy

 

Dealine is 26 January 2012 at 13.00.   ATTACHED YOU FIND ALL THE NEEDED DOCUMENTS!  Which you find also here .

We have 9 positions available starting between Jan and March 2012 on various themes of mechanical and management engineering at Politecnico di BARI .


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Mechanics of love and happiness

An interesting application of non linear dynamics, including happiness with a simple 1D damped oscillator!


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Frictional energy dissipation in contact of nominally flat rough surfaces under harmonically varying loads

Frictional energy dissipation in contact of nominally flat rough surfaces under harmonically varying loads  Original Research Article


Journal of the Mechanics and Physics of Solids, , Available online 1 October 2011,
C. Putignano, M. Ciavarella, J.R. Barber   View Abstract  


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A simple approximate expression for finite life fatigue behaviour in the presence of ‘crack-like’ or ‘blunt’ notches

After a long process (somebody may recall I made also quite some chaos on imechanica to complain with the review process in a previous journal), this paper was accepted.  Ask me a preprint if you are interested.  I can attach here a few images only.


M. CIAVARELLA
Politecnico di Bari, 70125 Bari, Italy
Received in final form 13 June 2011

 


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Benoit Mandelbrot dies at 85

Mandelbrot has passed away last week.  A very interesting  mathematician, who received tenure from Yale only at 75, he has introduced fractals also in fracture mechanics.

Benoit Mandelbrot, Father of Fractals, Dies at 85


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Neet generation, generation not-not, generacion ni-ni, many terms one meaning!

 

I think I have spoken various times of this problem.

In Italy there was today an announcement that we have the biggest such problem in Europe.  See here .

When I search in wikipedia, I find various terms.


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