Mike Ciavarella's blog
A seminar at Paris VI inst. d'alembert - One, no one, and one hundred thousand crack propagation equations: thursday June 5th. 1Submitted by Mike Ciavarella on Wed, 2008-06-04 14:06.
Prof Jean -Baptiste Leblond (http://www.lmm.jussieu.fr/~leblond/)
kindly invited me to give a seminar at Inst. d'alembert - Paris VI
A well-spent day brings happy
Leonardo da Vinci
All our knowledge has its origins
in our perceptions.
Leonardo da Vinci
commences with reason and ends in experience it is
us to do the opposite, that is to commence with experience
from this to proceed to investigate the reason.
Anyone who conducts an argument by appealing to
authority is not using
his intelligence; he is just using his
Leonardo da Vinci
Art is never finished, only
Leonardo da Vinci
As a well-spent day brings
happy sleep, so a life well spent brings happy
Does a scientist who has had three patents in the past five years, but only three papers, each cited just three times, deserve mSubmitted by Mike Ciavarella on Wed, 2008-06-04 13:05.
From the blogosphere
Nature 453, x (2008). doi:10.1038/7196xc
Does a scientist who has had three patents in the past five years,
but only three papers, each cited just three times, deserve more
recognition than one with five Nature papers and 1,000 citations?
Can anyone download the full paper I have no access to Nature!!!!
It is difficult to reminisce over my own formative years without sensing
the sharp contrast with the far more difficult situation faced by the
young generation today. My generation, and especially my own narrow age
range within that generation, had things easier, I think, than any group
before or after. I entered Lehigh for undergraduate studies one year
after Sputnik. It was a time when support for science and engineering
was enlarging fast, when opportunities were abundant. There were plenty
of graduate fellowships. There were also generous loan programs, fully
forgivable for those who went into teaching. I had both at Lehigh, where
I also stayed for graduate studies. Getting a postdoc position could be
Leonardo da Vinci the precursor of Publish AND Perish ---- not Publish OR Perish -- the present model is dead!Submitted by Mike Ciavarella on Sat, 2008-05-31 13:53.
Dear Imechanica friends
I recently pointed to a very interesting paper by Fabio Casati and collegues from Trento University in Italy.
They say PUBLISH AND PERISH: WHY THE CURRENT PUBLICATIONAND REVIEW MODEL IS
KILLING RESEARCH AND WASTING YOUR MONEY
as opposed to the current mania to PUBLISH and killing yourself with writing papers.
Liquid Publications: Scientific Publications meet the Web ¶
Some very interesting projects from University of Trento. Changing the way scientific knowledge is produced, disseminated, evaluated, and consumed
dear Elsevier Editors and boards
after I submitted to the Harvard blog imechanica.org
"My letter of resignation from the board of International Journal of Solids and Structures"
Submitted by Mike Ciavarella on Tue, 2008-05-20 14:55. www.micheleciavarella.it
which received so far 1812 reads in only 2 days, I have received many letters that jammed
my E-mail system. To continue my normal operation, since this is not expected as a
full-time occupation, I therefore decided to create, according to many people's suggestion,
Dear Imechanica friends: in connection to the www.engineeringchallenges.org and Roberto Ballarini post suggesting the presidential Candidates Obama, Clinton and McCain do not seem to respond to the Sciencedebate2008, and see the call for "Science White House" by Nobel prize winners David Baltimore and Ahmed Zewail, the USA seems to be in a big Science Crisis, which is called already in Scientific Literature the American PARADOX (see below). In very short, this is due to the fact that the ONLY real big thing for the American (and European) public is Sport and TV stars. There is "legs-drain" of David and Victoria Beckham ---- the public and politicians do not care of the "brain-drain" of best people like for example people who already running operations in both US and in Asia (see the A* program in Singapore). And not even of Nobel-prize-winner-drain!!!
Zhigang, about defining "esthablished", I am worried people may consider arbitrary your "definition" -- not me, you can do as you like!
But look that even somebody as weak as me could be in the list you propose!!, and for different criteria! Only Nix and Hutchinson really stand high in the lists as "esthablished". Incidentally, congratulations: the most cited paper of Hutchinson is that with you.
I have promised more replies on Mandelbrot, fractals, strongly emotive discussions in journals, and here is a coincise statement, which I take from a Nobel prize, prematurely passed away last year. I think it has a lot to teach (including the kind of attitude that leads to Nobel prize, i.e. close to no human weakness), you will recognize the real name of the "Caesar" in this book is somebody with a 58 pages CV on his web site, most likely.
For a better idea of fractals, read please the other attachment.
"trivial history" ?? Maybe Leonardo deserves a Timoshenko medal !! - a reply to Arash_Yavari comment on review of paper by HDBuiSubmitted by Mike Ciavarella on Thu, 2008-04-17 17:53.
Arash, I am quite shocked by your reply http://imechanica.org/node/3045#comment-7151. First you say "with all the due respect", then you say "trivial history". But you prudently say "maybe I miss the point". Maybe useful to clarify, also because probably iMechanica should start a discussion about history of mechanics starting a little earlier than this century. How can we judge Leonardo da Vinci? He has no published papers, no citation, no index, no Nobel prize... Not even a Timoshenko medal! Maybe we should give him one post-mortem? Please see the attachment. Watch also the videos:
I think it would be useful to collect a list of most useful sites, to start with iMechanica-look-alike. Not exactly similar but a good site for CFD is http://www.cfd-online.com/. This incidentally suggests us some "ways" to improve iMechanica. (see my other blog PROPOSAL for iMechanica http://imechanica.org/node/2996)
dear iMechanica friends
I came across a review of a paper by HD Bui who was somewhere in the internet, and I find it is very interesting. I could even have written this review myself !! I don't think the reviewer exaggerates....
You may remember that I promised some time ago to discuss each of the topics mentioned by Ken Johnson in his Timoshenko Medal speach. Here I take rail corrugation. Rail corrugation has been noticed at least for 100 years, but (particularly short pitch one in the range 20÷80 mm) has been considered an enigma because measured corrugation wavelength did not relate well with wear instabilitymodels.
Hello imechanica users: I launch a few ideas. Can we improve imechanica stealing ideas from successful web systems like google, amazon, wikipedia, myspace, youtube? Taking the best of the various worlds to improve our imechanica?
Recent experiments in sliding friction are a major embarassment for all present understanding of friction using Coulomb or Rice-Ruina-Dieterich-Prakash rate-state dependent theories, which are the subject of large research programs. In particular, Rubinstein et al; (Detachment fronts and the onset of dynamic friction. Nature 430, 1005—1009. 2004) suggest that the contact area is not significantly altered by the fast fronts which perhaps are only precursors to the most important "slow fronts" travelling at speeds about 1/10 of the Rayleigh speed.
dear Imechanica users,
a wonderful location for our annual italian conference in stress analysis -- see www.aias2007.it. It is organized by our collegues in Università di Napoli, Prof. Renato Esposito. Attached the call for papers in PDF, and more info are below.
I am trying to find out the theoretical adhesive strength limit of a few materials, or more precisely the ratio adhesive strength limit to elastic modulus. I think this is after all part of the Lennard-Jones constants potential - theoretical adhesive strength limit is simply the maximum of the curve.
A recent string of papers originated from Persson's paper in the physics literature contain a number of interesting new ideas, but compare, of the many theories for randomly rough surfaces, only Persson's and Bush et al, BGT. These papers often assume the original Greenwood and Williamson (GW) theory  to be inaccurate, but unfortunately do not test it, assuming BGT to be its better version. The original GW however is, I will show below, still the best paper and method today (not surprisingly, as not many papers have the level of 1300 citations), containing generally less assumptions than any other model, including the constitutive equation which does not need to be elastic! I just submitted this Letter to the Editor: On "Contact mechanics of real vs. randomly rough surfaces: A Green's function molecular dynamics study" by C. Campaña and M. H. Müser, EPL, 77 (2007) 38005. C. Campaña and M. H. Müser also make several questionable statements, including a dubious interpretation of their own results, and do not even cite the original GW paper; hence, we find useful to make some comments.
As I promised, I start with some brief notes on themes loved by Ken Johnson to hopefully raise some interest for discussion on iMechanica. Regards, Mike
Anders Klarbring, Jim Barber and I are preparing a paper on the subject of shakedown in elastic contact problems with Coulomb friction. In particular, we establish the (rather limited) conditions under which a frictional equivalent of Melan's theorem can be applied, and we counterprove the theorem in all other cases.There is no plasticity here - the contacting bodies are linear elastic - but the analogies between the Coulomb friction law and elastic plastic deformation make us think the plasticity community might be interested in the results.