iMechanica - stress - Comments

Re: Problems with WIkipedia

Biswajit Banerjee — Tue, 22 Jul 2008 20:10:54 -0400

You're right Mike.

A problem that I've run into is that some people tend to be very possessive of a particular wiki page. Sometimes a correction that I make is reverted back by the "owner" of the page. What's amazing is that Wikipedia still contains some valuable and accurate information - though I wouldn't bet anything on the accuracy bit.

-- Biswajit

Biswajit, these wiki people seem confused about other issues...

Mike Ciavarella — Tue, 22 Jul 2008 17:27:01 -0400

We really need some good people to deal with this wiki page, if you read my recent post Some news from WIKIMANIA / change in the system this is one case were we really need some "administrator" with better grasp on the field, before Wikipedia gets it published. Maybe you should contact the wikipedia top people to ask if "imechanica" can be in turn this "administrator" !

Read the other point and how poorly it starts :(

Brittle and ductile

I am skeptical about "By definition, brittle materials fail under
normal stress, and plastic or ductile materials fail under shear
stress." Don't ductile materials undergo plastic yield before failing
whereas brittle materials simply break? (I am in the midst of a stress
class; if nobody touches this, I'll come back to it later.)

Re: Seriously?

Biswajit Banerjee — Tue, 22 Jul 2008 17:07:41 -0400

Chad,

I had a brief glance at the page last night. But the more interesting point, in my view, was that he had managed to get his papers published! Now that we have had a few comments on iMechanica, I'll post a link to this discussion on the discussion page on Wikipedia for the benefit of other confused readers there.

-- Biswajit

Quite a rich comment. You are right, we need to ask ourselves...

Mike Ciavarella — Tue, 22 Jul 2008 16:58:27 -0400

... about the clarify of our "fundamentals" and indeed this guy has been asking himself so much that he is now all confused! ;)

Re: A new theory of stress?

Ajit R. Jadhav — Tue, 22 Jul 2008 16:31:06 -0400

(0.0) I went through some of Mr. Koenemann's papers / documents / Web pages today. Here are my initial impressions (which are unlikely to change much).

(1.0) Initial impression gathered from his writing style: Even in his serious papers, he seems to jump from topic to topic far too easily---even carelessly. For example, see the "Conclusion" part of his paper "Gibbs.pdf," the one which is supposedly accepted for pub. in IJMPB. (BTW, I checked the site of this journal, but they do not list any of their forthcoming papers.) It is next to impossible to even guess what he might be thinking in going from one step to another step---if the statements can be called "steps".

(2.0) His "Logic": In his easiest to read (for me) paper, i.e. "Systematics.pdf" (published in 2004), the "position" from which his arguments flow began to become somewhat clearer. The way I understand his position, his essential logic seems to be the following:

(2.1) He says in this paper (and I quote) that "div \vec{f} is a measure of the work done by/upon a system."

Hello? My understanding is that for certain vector fields like the static electric field, \vec{f} can be given as the gradient of a scalar potential function, say, \phi. (This, of course, is not universally true though that's what he seems to assume.) In the cases where this condition holds, it is \phi which represents work/energy---not div \vec{f}. What does divergence of \vec{f} have to do with __work__? I fail to see this. In fact, in electrostatics, div \grad\phi would give you the stored __electric charge density__, not the stored __work__. But still, in this paper, work, it becomes. Why? Apparently, simply because he thinks so.

I wonder why none noticed such a prominent and so simple a mistake in the review process... (Has anyone checked whether these papers were even actually published in those journals?)

(2.2) He then tries to apply this (wrong) premise of his to the div of the stress vector. Now, in stress analysis, div \vec{T} = 0 (using momentum and torque balance). On this basis, he concludes (using his above-mentioned wrong idea) that no __work__ is done during a volume-constant deformation....

Now that is some conclusion to draw!!

(3.0) In another paper: "thoughts.pdf" (published in 2001), he says: "General solutions for the Poisson equation exist only for reversible processes, e.g. the Helmholtz equation." [sic]

Phew! At this point, I stopped reading all the __published journal papers__ of his.

(4.0) The interesting part is not whether what he has written is right or wrong (i.e. true or false). That issue is relatively simple to settle: obviously, what he writes is so absolutely false.

But a more interesting part is: What does it say about the review process of today's journal articles? ... You see, it was only yesterday that I was talking to some gentleman who mentioned to me: "But all that you have published during your PhD studies are conference papers, no journal papers... Your conference papers will not be counted..." And I found myself wondering aloud, once again: How does it matter? I even remembered the Bogdanov brothers incidence (which I had come to know from David Harriman's article). I mean, it does not seem likely, but still, it is possible that some journal might publish such articles...

If the journal review system also is not going to provide that gentleman with any guaruntees or assurances of the kind that he was seeking and presuming, why does he insist on that? Now, that is one issue which is much more interesting to me.

(5.0) However, the most interesting issue, for me, is that when a piece of writing like this does come along, what does it do to you.... Doesn't it force you to examine the clarity of your own fundamentals, even if only for an hour or two---before you find the author out? Even if only because the speaker has been using the terms so casually and indiscriminately? Not as a matter of some naive or honest mistake, but out of a deliberate kind of gliding over of the relevant facts? One is not accostomed to that kind of writing in science, and so, simply because the author throws a lot of incommensurate concepts together in a rapid succession, it begins to challenge your mind. So, there is a value to it in a weird, even humorous, sort of way...

I mean, in a way, a "paper" of this kind does serve to expose the weak spots in your own understanding, too...

For instance, have a look at these concepts/ideas which come up repeatedly while going through some of Mr. Koenemann's published journal papers.... Some aspects of these basic concepts have stumbled me quite a lot in the past... Why, some aspects have stumped me even in a very recent past---as late as a year or two back:

-- What is the essential difference between a field theory and a particle theory? (This question is relevant because what he describes as Newton's theory actually seems to refer to the "particle" kind of description. This, he seems to want to differentiate from the field abstraction.)

-- Why is pressure generally regarded as a scalar quantity when it is well known that the air actually is forcing the rubber walls of a balloon out?

-- What conceptual steps are involved before the Newtonian idea of force (something which acts on a particle to change the course of its motion) can be brought into the analysis of a continuum phenomenon, i.e. a field? For example, a vector field? A scalar field? How about tensor fields? Is particle really a point-phenomenon? Or does it, too, represent a differential-element-based abstraction?

-- What precisely are the physical dimensions of the potential functions used in the analytical stress theory? More important: Why do respectable authors never mention this in their books? (Here, feel free to pick any book/paper you like.)

-- What, precisely, is the difference between the meaning of the term "potential" when this term is used in electrostatics as against in stress analysis?

-- Can you reduce (3D) stress, a tensor, to a "collection" of three vectors? Why? Why not?

(6.0) All in all, an interesting Web site!!

This discussion is curious: you hope to find the "holy graal"..

Mike Ciavarella — Tue, 22 Jul 2008 16:25:01 -0400

I fully understand that it would be good to discover something great of the past that has been completely misunderstood or neglected.

So the entire Chauchy stress framework is flawed and only this guy knows it.

I also understand that there is some kind of annoyment to be aligned like number 12500 who cites the "fractal geometry of nature" from Benoit Mandelbrot

Yet, I suspect it is much more profitable to read Benoit Mandelbrot despite 12500 papers have already found and cited him (so I suspect at least 100 000 have read it), rather than following the chimera that Chauchy was wrong and that this guy who maybe does not even exist, and who has no previous record, nor present record, claims.

So why not finding the 10 000+ books and papers that really matter, and start discussing, or perhaps mixing them up?

I have provided 2 examples. The discovery of Carbon Nanotubes, and the "discovery" of fractals. Please provide other examples, and we shall make progress. I do not beleive in Holy Graal!

Actually, if you really want to hope to discover something, there is more chance to do it in Leonardo da Vinci. His latest books were found in Madrid in 1970, and contain a lot of mechanics. Roberto Ballarini recently wrote that in this codes, Leonardo clearly had already solved Beam Theory, well before Euler and Bernoulli, let alone the wrong theory of Galileo, and before not only Chauchy concept of stress, but even Hooke's concept of Elasticity!

"The Da Vinci-Euler-Bernoulli Beam Theory," ME Online Web ...

I challenge you then to go to Madrid and read Leonardo -- you may discover, like Ballarini, that he had something there.

I have for example just finished reading Capra's book on Leonardo

Fritjof Capra - The Science of Leonardo

It is a good book, and opens the mind. There is a lot of Leonardo that is being rediscovered and is still not yet appreciated, particularly his ideas about ecology.

New Book: The Science of Leonardo

From the Preface:
Leonardo da Vinci, perhaps the greatest master painter and genius of
the Renaissance, has been the subject of hundreds of scholarly and
popular books. His enormous oeuvre,
said to include over 100,000 drawings and over 6,000 pages of notes,
and the extreme diversity of his interests have attracted countless
scholars from a wide range of academic and artistic disciplines.

However,
there are surprisingly few books about Leonardo's science, even though
he left voluminous notebooks full of detailed descriptions of his
experiments, magnificent drawings, and long analyses of his findings.
Moreover, most authors who have discussed Leonardo's scientific work
have looked at it through Newtonian lenses, and I believe this has
often prevented them from understanding its essential nature.

Leonardo
intended to eventually present the results of his scientific research
as a coherent, integrated body of knowledge. He never managed to do so,
because throughout his life he always felt more compelled to expand,
refine, and document his investigations than to organize them in a
systematic way. Hence, in the centuries since his death, scholars
studying his celebrated Notebooks have tended to see them as
disorganized and chaotic. In Leonardo's mind, however, his science was
not disorganized at all. It gave him a coherent, unifying picture of
natural phenomena — but a picture that is radically different from that
of Galileo, Descartes, and Newton.

Only
now, five centuries later, as the limits of Newtonian science are
becoming all too apparent and the mechanistic Cartesian worldview is
giving way to a holistic and ecological view not unlike Leonardo's, can
we begin to appreciate the full power of his science and its great
relevance for our modern era.

My
intent is to present a coherent account of the scientific method and
achievements of the great genius of the Renaissance and evaluate them
from the perspective of today’s scientific thought. Studying Leonardo
from this perspective will not only allow us to recognize his science
as a solid body of knowledge. It will also show why it cannot be
understood without his art, nor his art without the science.

As
a scientist and author, I depart in this book from my usual work. At
the same time, however, it has been a deeply satisfying book to write,
as I have been fascinated by Leonardo da Vinci's scientific work for
over three decades. When I began my career as a writer in the early
1970s, my plan was to write a popular book about particle physics. I
completed the first three chapters of the manuscript, then abandoned
the project to write The Tao of Physics, into which I
incorporated most of the material from the early manuscript. My
original manuscript began with a brief history of modern Western
science, and opened with the beautiful statement by Leonardo da Vinci
on the empirical basis of science that now serves as the epigraph for
this book.

Since
paying tribute to Leonardo as the first modern scientist (long before
Galileo, Bacon, and Newton) in my early manuscript, I have retained my
fascination with his scientific work, and over the years have referred
to it several times in my writings, without, however, studying his
extensive Notebooks in any detail. The impetus to do so came in the
mid-1990s, when I saw a large exhibition of Leonardo's drawings at The
Queens Gallery at Buckingham Palace in London.

As
I gazed at those magnificent drawings juxtaposing, often on the same
page, architecture and human anatomy, turbulent water and turbulent
air, water vortices, the flow of human hair and the growth patterns of
grasses, I realized that Leonardo's systematic studies of living and
nonliving forms amounted to a science of quality and wholeness that was
fundamentally different from the mechanistic science of Galileo and
Newton. At the core of his investigations, it seemed to me, was a
persistent exploration of patterns, interconnecting phenomena from a
vast range of fields.

Having
explored the modern counterparts to Leonardo's approach, known today as
complexity theory and systems theory, in several of my previous books,
I felt that it was time for me to study Leonardo's Notebooks in earnest
and to evaluate his scientific thought from the perspective of the most
recent advances in modern science.

Although
Leonardo left us, in the words of the eminent Renaissance scholar
Kenneth Clark, "one of the most voluminous and complete records of a
mind at work that has come down to us," his Notebooks give us hardly
any clues to the author's character and personality. Leonardo, in his
paintings as well as in his life, seemed to cultivate a certain sense
of mystery. Because of this aura of mystery and because of his
extraordinary talents, Leonardo da Vinci became a legendary figure even
during his lifetime, and his legend has been amplified in different
variations in the centuries after his death.

Throughout history, he personified the age of the Renaissance, yet each era "reinvented" Leonardo according to the zeitgeist
of the time. To quote Kenneth Clark again, "Leonardo is the Hamlet of
art history whom each of us must recreate for himself." It is
therefore inevitable that in the following pages I have also had to
reinvent Leonardo. The image that emerges from my account is, in
contemporary scientific terms, one of Leonardo as a systemic thinker,
ecologist, and complexity theorist; a scientist and artist with a deep
reverence for all life, and as a man with a strong desire to work for
the benefit of humanity.

Click here for the book tour schedule.

ZAMM

Roozbeh Sanaei — Tue, 22 Jul 2008 15:45:52 -0400

I had seen questionable papers in ZAMM but not very radical! who is reviewer?

But if the paper is NOT published, I cannot cite it !!! ;(

Mike Ciavarella — Tue, 22 Jul 2008 15:37:11 -0400

michele ciavarella
www.micheleciavarella.it

OK, someone should cite it for the first time!

Roozbeh Sanaei — Tue, 22 Jul 2008 15:31:07 -0400

someone should cite it for the first time! at least an erratum.

Koenemann's papers

Charles Augarde — Tue, 22 Jul 2008 15:26:12 -0400

I came across this website a few years ago and thought it interesting
but got no response on the Usenet groups to discuss these ideas so I am glad to see something on imechanica. I found some of it hard to follow.

The website used to carry some tales of his efforts to get papers published which were entertaining, but these appear to have disappeared and I can't find them archived (the URL was different from my memory).

I guess I would be keen to make sure there is nothing of value in these ideas, and/or they have serious flaws, which appears to be the impression from the posts so far.

Anyone care to drop the chap an email?!!!

Regards

Charles

I am not sure any of his papers are accepted, plus zero cites !

Mike Ciavarella — Tue, 22 Jul 2008 14:46:00 -0400

This guy is a joke. Don't waste time. You find only preprints in Archiv http://arxiv.org/ftp/physics/papers/0103/0103010.pdf

and there the few citations are self-citations.

Maybe the guy is real and is just playing with you. Now he had his 5 minutes celebrity, that's it !

Regards Mike

Query: "Koenemann FH": all
Summary: <<
Papers:    9    Cites/paper:    1.00    h-index:    2    AWCR:    1.00
Citations:    9    Cites/author:    9.00    g-index:    3    AW-index:    1.00
Years:    16    Papers/author:    5.83    hc-index:    2    AWCRpA:    1.00
Cites/year:    0.56    Authors/paper:    1.44    hI-index:    2.00
                hI,norm:    2

Hirsch a=2.25, m=0.13
Contemporary ac=1.00
Cites/paper 1.00/0.0/0 (mean/median/mode)
Authors/paper 1.44/1.0/1 (mean/median/mode)

1 paper(s) with 0 author(s)
4 paper(s) with 1 author(s)
3 paper(s) with 2 author(s)
1 paper(s) with 3 author(s)
>>

Cites,Authors,Title,Year,Source,Publisher,ArticleURL,CitesURL
4,"FH Koenemann","Cauchy stress in mass distributions",2001,"Arxiv preprint physics/0103010","arxiv.org",

"http://arxiv.org/abs/physics/0103010",

"http://scholar.google.com/scholar?num=100&hl=en&lr=&cites=2571967473311119441"
3,"FH Koenemann","Unorthodox Thoughts about Deformation, Elasticity, and Stress",2001,"Zeitschrift für Naturforschung. A, A Journal of physical …","znaturforsch.com","
http://znaturforsch.com/aa/v56a/56a0794.pdf","http://scholar.google.com/...
2,"FH Koenemann","Tectonics of the Scandian orogeny and the Western Gneiss Region in southern Norway",1993,"International Journal of Earth Sciences","Springer","
http://www.springerlink.com/index/Q8520JU4TK523267.pdf","http://scholar....
0,"FH Koenemann, I Johannistal","On the systematics of energetic terms in continuum mechanics, and a note on Gibbs (1877)",0,"elastic-plastic.de","","
http://www.elastic-plastic.de/Gibbs.pdf","http://scholar.google.com/scho...
0,"H Forster, FH Koenemann, U Knittel","Regional framework for gold deposits of the Odzi-Mutare-Manica greenstone belt, Zimbabwe-Mozambique",1996,"Transactions of the Institution of Mining and Metallurgy. …","","","
http://www.google.com/search?hl=en&lr=&q=Forster+Regional+framework+*+go...
0,"","Linear Elasticity and Potential Theory: a Comment on Gurtin (1972)",0,"","","","
http://scholar.google.com/scholar?num=100&hl=en&lr=&q=related:xa3JQfIzLW...
0,"FH Koenemann, I Johannistal","A Reevaluation of the Cauchy Stress Hypothesis",0,"elastic-plastic.de","","
http://www.elastic-plastic.de/re-eval.pdf","http://scholar.google.com/sc...
0,"FH Koenemann, I Johannistal","An approach to deformation theory based on Boyles law. IV. Application to a discrete body problem",0,"elastic-plastic.de","","
http://www.elastic-plastic.de/Theo4.pdf","http://scholar.google.com/scho...
0,"FH Koenemann","Origin of Oblique Microfabric Orientation in Simple Shear Zones",2000,"","agu.org","
http://www.agu.org/cgi-bin/wais?q=T11C-04","http://66.102.1.104/scholar?...

PDF] Unorthodox Thoughts about Deformation, Elasticity, and Stress - all 5 versions »
FH Koenemann - Zeitschrift für Naturforschung. A, A Journal of physical …, 2001 - znaturforsch.com
The nature of elastic deformation is examined in the light of the potential
theory. The concepts and mathematical treatment of elasticity and the choice of
equilibrium conditions are adopted from the mechanics of discrete bodies, ...
Cited by 3 - Related Articles - View as HTML - Web Search - BL Direct

[CITATION] Linear Elasticity and Potential Theory: a Comment on Gurtin (1972)
FH Koenemann
Related Articles - Web Search

[PDF] On the systematics of energetic terms in continuum mechanics, and a note on Gibbs (1877)
FH Koenemann, I Johannistal - elastic-plastic.de
The systematics of energetic terms as they are taught in continuum mechanics
deviate seriously from the standard doctrine in physics, resulting in a profound
misconception. It is demonstrated that the First Law of Thermodynamics has ...
Related Articles - View as HTML - Web Search

[PDF] A Reevaluation of the Cauchy Stress Hypothesis
FH Koenemann, I Johannistal - elastic-plastic.de
The theory of stress is solidly based on the cut model of Euler which was used
by Cauchy to derive the stress tensor. The cut model considers a group of planes
passing through a given point Q in space, and the system of forces acting ...
Related Articles - View as HTML - Web Search

PDF] An approach to deformation theory based on Boyles law. IV. Application to a discrete body problem
FH Koenemann, I Johannistal - elastic-plastic.de
The approach to deformation theory is used to model the distribution of the
failure potential in a discrete body subjected to a specific loading
configuration in 2 dimensions. The Fourier series method is applied, and it ...
Related Articles - View as HTML - Web Search

[CITATION] Linear Elasticity and Potential Theory: a Comment on Gurtin (1972)
FH Koenemann
Related Articles - Web Search

Koenemann's papers

Rui Huang — Tue, 22 Jul 2008 13:46:42 -0400

First I am relieved to see Chad's reponses to the five questions. I was thinking that would be a good place to start in order to address Koenemann's issues. Then I thought it may be better to read a couple of his papers to know more about his thinking. I printed out his "comment on Gurtin (1972)" and "note on Gibbs (1877)". After reading the first, my desire to read on of his papers drops significantly. I can't understand how the paper is accepted for publication in a physics journal. Does anyone know about International Journal of Modern Physics B? The entire paper is based on his own guess or assumption of what Gurtin knew. It reads like a presonal attack in politics.

I am not sure if I am going to read the second paper.

Thanks

Mike Graham — Tue, 22 Jul 2008 12:59:08 -0400

Thanks for the advice. I am not taking Koenemann extremely seriously, but I figure there might be something there. His website is not as cooky as I'd usually expect from a troll. It looks like he tried to plainly show what he was talking about on the poster page, but the math was unreadable due to display issues. At the least, it might sharpen my idea of why we do continuum mechanics like we do.

Responses to Mr. Koenemann

Chad Landis — Tue, 22 Jul 2008 12:51:56 -0400

Although I doubt Mr. Koenemann will read this post, I thought I might try to address some of the questions he posts on his site. These are very short answers, and in some cases there is a deeper discussion that may be required. The numbered questions are his, and the answers are mine.

For his comments on these questions go to:

http://www.elastic-plastic.de/Hp-5point.htm

It actually might be a good exercise for students to think about these questions and how to answer them.

1. Why do you use an equation of motion and not an equation of state?

Ans: In continuum mechanics one uses both an equation of motion and an equation of state.

2. Why do you use Newton's equilibrium condition and not the thermodynamic equilibrium condition which distinguishes system and surrounding?

Ans: Newton's equilibrium condition and what I believe you mean by "thermodynamic equilibrium" are independent concepts. Again, continuum mechanics uses both.

3. There are bonds in solids, but there's no mention of bonds in this theory. Aren't bonds important for the understanding of a solid?

Ans: Certainly bonds are important for understanding the behavior of solids. With the appropriate assumptions the stored energy in the bonds can be related to the strain energy of the solid (i.e. the equation of state of the solid).

4. Newton defined a rotating force as being perpendicular to the radius of a body. Here you define a shear force as being perpendicular to the normal of a planar element, which is an unit vector. These definitions are incompatible with one another because the magnitude of the radius vector can vary with direction whereas the unit vector cannot. Why do you believe that Newton's definition is wrong?

Ans: Although I am not familiar with Newton's definition of a rotating force (did he really define this?), these definitions appear to be independent and so are not incompatible. I do not see what the issue is here.

5. If you deform a body, say, a circle, by stretching it in X, work is done upon the body in X. Let's say this is negative work. But the body will contract in Z, so positive work is done in Z. If the volume remains constant, the work in X and the work in Z must balance, so no net work is done. Isn't this impossible?

Ans: First, if you stretch a body, the work done to stretch it will not be negative unless the body is unstable. The contraction in "Z" has no work associated with is unless there is a force in the "Z" direction during the "X" stretching process.

I doubt you need to read the papers.

Chad Landis — Tue, 22 Jul 2008 12:48:53 -0400

Michael,

Reading his papers is not likely to be worth your time. From your post it is clear that you have a better understanding of mechanics than Mr. Koenemann. There are certainly fundamental questions to be addressed in continuum mechanics and thermodynamics, but I do not think these are the ones.

Chad