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ME版 - Harvard professor John W. Hutchinson is accused of plagiarism
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相关话题的讨论汇总
话题: gurson话题: your话题: model话题: my话题: shear
进入ME版参与讨论
1 (共1页)
b***s
发帖数: 65
1
from: Liang Xue
to: John Hutchinson
cc: Tomasz Wierzbicki
date: Mon, Aug 11, 2014 at 12:12 PM
subject: Re: No winners--follow-up
Dear John,
Thank you for your email. I had a difficult time to understand the
message you want sent. My guess is that the central message you would like
to emphasize is that you can develop the same model once you understood that
ductile fracture is indeed J3 dependent. Possibly. I
believe many people have the necessary knowledge to do so on their
own. However, that is a hypothetical question. You were not given the
chance to develop it before you learned it from me.You will have to be
honest in that you are just following my approach in modifying Gurson
type model for shear failure. Your localization analysis is fully
based on your follow-up shear modified Gurson model. That doesn't make your
work independent of mine - you just analyzed it and found indeed my model is
exactly what it is supposed to be.
You probably forgot you mentioned "A modification of the Gurson Model
employing the Lode parameter has been pursued by Xue (2007a, 2007b)." on
page 14 of 2008 paper with Nahshon. There is no room for you to say you are
not aware of my model until now. Even you said you don't know my journal
paper, proper reference to my thesis is surely necessary - it is Chapter 12.
Ken Nahshon and Zhenyu Xue also cited my 2008 modified Gurson model journal
paper earlier in their 2009 paper "A modified Gurson model and its
application to punch-out experiments" in Engineering Fracture Mechanics.
They put the nucleation term back, which was in my original model, but you
neglected in your 2008 paper.
Your recent propaganda that you are first or independently developed
the shear modified Gurson model will ultimately fail. Everybody in the
mechanics community will eventually learn that you are just following
my work. What you are doing now will only affect how other will think
about you and how you will be remembered. If you continue your false
claims, ultimately, you will be the naked king standing on the podium
lying to the entire audience - each and every one of them knows you
are lying. You like that?
You took the advantage of sitting in my thesis committee learning my
unpublished work and later claim you didn't learn anything from me.
The recent action of you and your group has significantly undermined
my credit, creditability and reputation. You understand that I hold
you responsible for these damages to myself and my work. With your
previous extremely offensive all-lie email, you betrayed me who gave
you best opportunity to learn and spent time advised you the most
exciting development in this area in the past 30 years or so. You said
you are aware of the shear deficiency of Gurson-type model. Obviously
you have not the least clue on how to attack this problem before you
joined my thesis committee. I not only gave you the key to solve it
and also gave your my model. Without me, you and your group will be
just like others still scratching their heads for what is wrong with
the Gurson model. And you turned back to me and said to the whole
world that you developed it - is this how you pay me back? Is this how
you treat a friend?
You may have talked a lot of J3 dependence in the public - I believe
that is mostly for your own benefit, I doubt if that was ever not
followed by saying you developed a shear modified Gurson model.
Neither knowledge is created by you. Tom and me are certainly the real
whistleblowers for the new development of including J3 effect for
ductile fracture in this new century. The unwavering freedom in my
ductile fracture research from Tom is certainly the best support I
needed, without which I cannot move forward. If I insisted arguing
something, there must be a reason. Without any doubt, everybody has
benefited from my perseverance. If I had gave up, the state-of-the-art
of ductile research will not be at its current status. Moreover, I
learned most recently that the low cycle fatigue work I did at MIT
(another chapter in my thesis) is now being recommended to the
European pipeline industry for standard to replace Manson-Coffin's
law. I doubted if I have convinced anyone in my thesis committee for
that part when I was at MIT, but with the unbeatable research
environment at MIT, I am able to put that into my thesis. It was
recognized by the public now - I didn't even advertise that work.
You are like a naughty child guest that broke into host granny's
jewelry box, took the gold and then show-off to the world that you
discovered gold. After being caught, you denied everything until being
spanked. You have to face the fact. I understood the frustration you
had when you first learned J3 dependence and the shear modified Gurson model
from me. Knowing there is an issue, but not able to solve it for long time
- this is certainly painful. Suddenly, the issue was solved
by a student who you have never heard of and lived only 3 miles away
from you office at the other university at Cambridge. I guess you were
very sad at that time. Years passed, your frustration turned into
anger as the model spread around. Anger turned into desire eventually
and now you want desperately to be recognized as the first person or
independently developed the shear modified Gurson model. This is
simply not the truth.
Well, I have said a lot - it is all about you. I will let you decide
what you would like to do next. Why not put yourself in the big
picture - in the shoes of a great mechanician, a great educator? How
will he do? It is all up to you as for what kind person you want to
be. I am afraid that I am not the right person to give you suggestion
on that aspect. If you desperately want to fight this war, I have no
choice but to fight back. If you win, the entire Harvard faulty
members lose. If you win, the whole solid mechanics community loses.
If you win, this internet era loses.
Sincerely yours,
Liang
from: John Hutchinson
to: Tomasz Wierzbicki
Liang Xue
date: Tue, Jul 22, 2014 at 4:17 AM
subject: Re: No winners--follow-up
Dear Liang--
I would like to follow-up on Tom's message below by emphasizing several
points. First, as Tom notes, your 2008 paper on the Gurson model, which
neither Ken nor I were aware of until a few days ago, clearly demonstrates
your strength and insight as solid mechanican. As Tom also notes, there
were times on your committee when it was frustrating to us on the committee
that you seemed to be spreading yourself too thin by trying to cover too
many aspects of the subject. I have to add to this that at the same time,
it was clear to me, and I believe to us all, that you had unusual talent,
energy and technical ambition. If my referencing of your work has not
reflected this, I apologize. Of course, I can't apologize for not
referencing a paper I have not read, but I guess I should apologize for not
having made more effort to search out other papers (not only yours, one of
Tom's too!--see below) when I wrote the paper with Z. Xue and Faleskog.
Like Tom, I do not spend much time researching earlier work when I work on
problems (certainly not as much time as I should). And I do not pay any
attention to blogs--I almost never consult iMechanica. For example, I was
unaware of your first 2012 post on iMechanica until the other day when Ken
turned it up.
Let me try to address one other point. You are correct that when I first
heard about the Bao-Wierzbicki experimental results I was very skeptical.
In fact, everyone of my colleagues in fracture whom I spoke to about the
Wierzbicki work expressed skepticism. I was one of the first supporters,
and perhaps the strongest advertiser, of these findings when I finally
accepted them. You may also be correct that that "my conversion" occurred
while I was serving on your committee--I don't remember the timeline, but
this is very possible. Once I accepted the validity of these experiments,
there was no alternative to conclude that J3, the Lode parameter, or
something like the omega parameter had to be involved. If an initially
isotropic metal strained proportionally to fracture displays behavior that
does not correlate with triaxiality, then J3 or L has to be involved. This
is fundamental knowledge that any strong solid mechaniker who works in
plasticity and fracture would realize. Tom has emphasized to me that you
were the one in his group that first realized the importance of J3 and L.
In fact, in another paper that Ken found the other day--the 2007 paper on 7
fracture criteria by Tom and several other authors--- I saw reference to a
report by you and Tom and a fracture criterion proposed by the two of you
which clearly highlights that axisymmetric stress state are an upper bound
while what you call plane strain states provide a lower bound. I again have
to admit (apologize) that I had not seen this before several days ago.
Coming at this through the shear localization analysis, this is exactly what
Ken and I found in our 2008 paper and what I emphasized in my recent paper
with Z. Xue and Faleskog, again backed up by the localization analysis. I
would have certainly referenced your earlier work on this had I been aware
of it. And I will clearly emphasize your early insights if I write further
on this subject. To me, the upper bound role for axisymmetric states and
lower bound role for what I can shearing states is one of the most important
insights to have emerged since the Wierzbicki experiments. I hope you can
understand that I did not "steal" this from you. This important result
emerged clearly from our localization analysis. The fact that two groups
arrived at the same understanding is a testimony to our abilities as
mechancians and to the power of mechanics. Again, I do admit that I should
have taken more effort in delving into the literature.
Finally, let me mention that I was aware when I agreed to serve on your
thesis committee that their might be some conflicts of interest. At the
time, I was heavily involved with a research effort headed by Tony Evans
which was concerned with being able to predict various kinds of shear-off
events, especially under blast loads. I was very much aware of the
inadequacy of the Gurson model as a constitutive model for such events. I
had hoped that by Ken and me focusing on the Gurson model we could maintain
a clear separation from your thesis research. I was clearly wrong on that
assumption.
I hope this detailed background will enable you to see that: 1) I have
high respect for your talents as a mechanician and 2) I have not in any way
abused my role as a member of your thesis committee. I do admit that I have
recently discovered aspects of your work that I was not aware of and I will
do my best to rectify this in any future papers I write on the subject.
As far as I am concerned, we still have the chance to end this recent spat
as friends and colleagues. Ductile fracture is a great subject that needs
all the talent and interest it can garner.
With my best wishes.
JOHN
from: Liang Xue
to: John Hutchinson
cc: Tomasz Wierzbicki
Ken Nahshon
Lallit Anand
David M. Parks
date: Sat, Jul 19, 2014 at 10:16 PM
subject: Re: academic ethics
Dear John,
I give you 24 hours to response, publicly. I give you chance to back off. If
you don't respond, more to come.
Sincerely yours,
Liang
from: Liang Xue
to: John Hutchinson
cc: Tomasz Wierzbicki
Ken Nahshon
Lallit Anand
David M. Parks
date: Wed, Jul 16, 2014 at 8:24 AM
subject: Re: academic ethics
Dear John (copying to Tom Wierzbicki, Ken Nahshon, Lallit Anand and Dave
Parks),
Thank you for your responding to my email. Your email has justified my
questioning of your integrity. My entire thesis committee had witness
your fight against my fracture models with corrections of J3
dependence. Therefore, I am also copying to Professors Lallit Anand
and Dave Parks at MIT besides Tom and Ken Nahshon who you have already
included.
I don't want to rebut your response line by line since most of them
are not true - especially you didn't mention when you started working
on the shear modification to Gurson model. Do you mind let us know the
timeline now and show the evidence? According to a private
converstation with your student Ken Nahshon, he was working on a
different topic for his thesis before you joined my thesis committe.
You don't even believe ductile fracture is J3 dependent at the time
you attended my first thesis committee in 2005. You put up quite a
fight on whethere the J3 dependence is truely exist and now you are
entirely backed off. I still remember you waved your hands and made
your remark that "Budiansky said no such effect" in MIT conference
room 5-314. There is no doubt that it was my first thesis committee
meeting that gave you a new perspective of ductile fracture. You
mentioned Bao and Wierzbicki's experiments. When Tom and me personally
invited you to my thesis committee at your office at Harvard in April 2005,
you said "No body believe it" regarding Bao and Wierzbicki's results. Your
frankness and boldness in language was remarkable and was very impressive to
me. You probably don't know who first interpreted Bao and Wierzbicki's
experimental results using Lode angle parameter and when that happened.
My shear modification to Gurson model was published first in 2006 in
the conference proceedings of the 9th European Mechanics and Materials
Conference. You may have already noticed my 2008 journal paper on shear
modified Gurson model is in a special issue of this conference in
Engineering Fracture Mechanics. By no means, your paper with your student
Ken Nahshon in 2008 will be considered the first model to describe the shear
effect to modify Gurson-type model. My 2006 EMMC9 paper was also given to
your student Ken Nahshon when he attended professor Wierzbicki's class in
2006. Anybody has read both papers will see the similarity, not to mention
there is no reasoning given in your paper as for how you get the form of the
shear damage term.
Putting the two models side by side, the only difference is that you
removed the nucleation term which is highly questionable and you have
chosen a different Lode angle dependence function, which is trivial in
that there are infinitely many such functions to give same values at
the three key points of generalized tension, shear and compression.
I suggest you make your response public, because my criticism to your
false claim of independently developed a shear damaged model is
public. If you mind your reputation, you really should respond
publically. Everyone in the mechanics community can make his/her own
judgement on whether your words are trustworthy.
I am not frustrated as I see my shear modified Gursom model has
aroused a lot of interest around the world. There are already several
Ph.D. theses compared your model with mine. I am proud of bringing
something new to you and having convinced you is my pleasure. It has
been quite an entertaining anecdote for me in the past years and years
to come. However, it does hurt my feeling about you, who I
respectfully invited to my thesis committee. My intention was correct
your false claim about the originality of shear modified Gurson model
if this has not concerned you so far. Let me repeat - it is about you,
not your work.
Sincerely yours,
Liang
from: John Hutchinson
to: Liang Xue
cc: Tomasz Wierzbicki
Ken Nahshon
date: Wed, Jul 16, 2014 at 3:43 AM
subject: Re: academic ethics
Dear Liang (copying to Tom Wierzbicki and Ken Nahshon)--
I am responding to your message below. Below that, I have also pasted
in the message you posted on iMechanica in late May on the same matter. I
decided not to reply publicly to your iMechanica post, but I will reply to
your e-mail to me. I am copying my response to Tom and Ken because this is
obviously relevant to them as well.
Let me begin by immediately correcting one of your assertions: I did
not learn about the inadequacy of the stress triaxiality characterization of
ductile fracture while on your thesis committee. I learned about this well
before I agreed to serve on your committee while attending one of Tom's
consortium meetings and hearing Tom talk about the Bao-Wierzbicki
experimental data. Sometime after that Tom asked me to serve on your thesis
committee. I agreed and, with the others on the committee, I tried to help
you focus your research.
In the 2008 paper Ken and I wrote on modifying the Gurson model, we
referred to your thesis and the 2008 paper by you and Tom of a modified
damage model which came out about the same time. We also referred to the
2004 paper by Bao and Wierzbicki. If you have read any of my papers on
ductile fracture or if you might have attended any lecture I have given on
ductile fracture in recent years, I have highlighted the fundamental
experiments of Bao and Wierzbicki and the essential role they have played in
advancing ductile fracture in the last decade. Most recently in my plenary
lecture on ductile fracture at the European Fracture Conference in
Trondheim, I used the Bao-Wierzbicki data in my first slide to emphasize
that triaxiality is not the only stress variable needed to characterize
ductile fracture. I had long been aware of the inadequacy of the Gurson
model as far as failure in shear was concerned. Moreover, going back to the
1970's there was already experimental data by Clausing showing that low
fracture strains could be attained under shearing stress states (and even a
data point or two in the Johnson-Cook paper). Let me also mention, that in
my most recent paper on ductile fracture with Zhenyu Xue and Jonas Faleskog
(2013) where we analyzed Faleskog's tension/torsion tests, I also cited your
2008 paper on your modified damage model.
The second point I would like to correct is that Ken and I did not take
any clue from you in our modification of the Gurson model in our 2008 paper
, but we were heavily influenced by the Bao-Wierzbicki experiments. Your
statement: "I am the person [who] advised John Hutchinson how to modify
Gurson-type model for shear failure of ductile metals" is certainly not true
. As an exercise for you, I would suggest you put your 2008 paper side by
side with our 2008 paper and take note of the differences. Your paper is
not really a modification of the Gurson model--it is a modified damage model
with little of the Gurson model retained. Ken and I made what we believed
was the simplest possible modification of the widely used Gurson model. The
fact that the Gurson model was so heavily used and that our modification
was relatively simple to implement is probably one of the reasons our paper
has received the attention it has.
I'm guessing you are frustrated by the the attention the Nahshon-Hutch
paper is receiving and this is what has motivated your two messages below.
You should not be frustrated. Your work in this area, particularly your
2008 paper, is also receiving plenty of attention. I hope you can get past
this frustration and appreciate the value of your own work.
Sincerely,
JOHN
On 7/14/2014 7:43 PM, Liang Xue wrote:
Home » Blogs » Liang Xue's blog
Academic ethics
Sat, 2014-05-31 11:22 - Liang Xue
I have been asked question that if John Hutchinson had given me help in
developing my shear modified Gurson model. This is indeed not a proper
question because I am the person advised John Hutchinson how to modify
Gurson-type model for shear failure of ductile metals.
In fact, the shear modified Gurson model was developed before Hutchinson
understood ductile fracuture is J3 dependent. John Hutchinson acquired these
knowledge when he sat in my thesis committee. It has been several occasions
that I was brought to attention that Hutchinson's group pretended that
their work on shear modified Gurson model is independent of my work and had
failed referencing properly to my original model of shear modified Gurson
model.
I am not sure if John Hutchinson had honestly told his student and post-doc
that the idea of adding shear damage term to the Gurson model is not his
original one but he learned it from me. I believe anyone should not pretend
the ideas of others to be their own whether those ideas are acquired from
thesis committee meeting or reading others' proposal or unpublished work.
from: Liang Xue
to: "John W. Hutchinson"
date: Mon, Jul 14, 2014 at 12:43 PM
subject: academic ethics
Dear John,
How are your these years? I haven't talked to you for a long time and
I learned you have retired and are now professor emeritus at Harvard.
The reason I contact you is that I have been brought to attention
recently that your group is pretending that the shear modification to
Gurson model is your original work. In a recent publication by you
student and co-author Ken Nahshon in International Journal of
Fracture, he explicitly claimed your paper in 2008 was the first one
to describe the shear damage to Gurson's model. This is highly not
true. You learned this method for adding shear damage term from me in
2005 when you were sitting in my thesis committee. It is your
responsibility to let your co-authors know where these ideas come
from.
And it is not the first time I was brought to attention on this. There
are several papers by you and your (former) colleague on the shear
modified Gurson model and its application failed to reference my
original work properly. I think you need to clarify with your student
that the shear modified Gurson model is not your original idea, if you
have not done so yet.
You are a well established researcher and I have no doubt that you
understand the right way of properly credit early works where you
learn from. I hope you will do things correctly.
Sincerely yours,
Liang Xue
1 (共1页)
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相关话题的讨论汇总
话题: gurson话题: your话题: model话题: my话题: shear