www.sefindia.org

STRUCTURAL ENGINEERING FORUM OF INDIA [SEFI]

 Forum SubscriptionsSubscriptions DigestDigest Preferences   FAQFAQ   SearchSearch   MemberlistMemberlist   UsergroupsUsergroups  RegisterRegister FAQSecurity Tips FAQDonate
 ProfileProfile   Log in to check your private messagesLog in to check your private messages   Log in to websiteLog in to websiteLog in to websiteLog in to forum 
Warning: Make sure you scan the downloaded attachment with updated antivirus tools  before opening them. They may contain viruses.
Use online scanners
here and here to upload downloaded attachment to check for safety.

Outstanding philospohers in Structural Mechanics(4)
Goto page 1, 2  Next
 
Post new topicReply to topic Thank Post    www.sefindia.org Forum Index -> SEFI General Discussion
View previous topic :: View next topic  
Author Message
Indrajit_Chowdhury
Bronze Sponsor
Bronze Sponsor


Joined: 06 Jul 2010
Posts: 26

PostPosted: Thu Oct 11, 2012 6:33 am    Post subject: Outstanding philospohers in Structural Mechanics(4) Reply with quote

Dear Sefians,
In my last two posting I had discussed two philosophers whose work helped structural engineering take great strides in terms of classical analysis (Timoshenko and Rayleigh) .
In the present posting we look into the work of two philosophers who brought a profound change in the analytical philosophy as was prevalent then. It was from this juncture, structural analysis got digressed to numerical analysis whose final outcome is finite element method as we see today. These two gentlemen invariably put structural engineering on a cross road and they are Prof. Carle Runge and Prof. Hardy Cross.
Carle David Tolme Runge (1858-1927):
Who would believe this man’s passion was literature - especially Anton Chekov [Of the famous work Seagull, Caucasian Chalk Circle, Grasshopper…...], and Norwegian Play writer Henrik Ibsen [Distinguished work A Doll’s House, Enemy of the people, Emperor and Galilean….]!!  
As a matter of fact, Runge enrolled himself to study literature in University of Munich and then after six weeks changed his mind to turn to physics and mathematics. He had another illustrious son of science as his class mate, none other than Max Planck (of the famed Planck’s constant in quantum mechanics), and they remained friends all their life. In 1877 both went to Berlin to do their Post graduate work while Planck turned to Physics, Runge turned to pure Mathematics, being influenced deeply by Weierstrass’s lectures and came out with a PhD in mathematics from University of Berlin in 1880 where his dissertation topic was differential geometry.  
After obtaining his PhD, he joined Faculty of Berlin University and worked under another great mathematician Kronecker (of the famous Kronecker delta function we use in structural dynamics), under whom he worked on a procedure for numerical solution of algebraic equations in which the roots are expressed as infinite series of the rational functions of the coefficients.
In 1904, Felix Klein who was then director of Gottingen University offered Runge a faculty position in the department of applied mathematics, which he accepted and remained therein till he retired in 1923.
In 1908 he published a paper in Z Math Phys (Vol.56 pp 225), wherein he showed how Laplace’s differential equation used in elasticity to define the torsional behavior of a beam be solved by finite difference method(FDM), where a differential equation is ultimately reduced to solution of a system of linear algebraic equations.  
Considering the paper was published in German, English speaking world hardly took notice of it except two i) L.F. Richardson from Imperial College of Science and Technology, and ii) Stephen Timoshenko (he is really a hawk eyed guy who rarely missed a good work, moreover considering his close proximity to the faculty of Gottingen through Ludwig Prandtl, he possibly had access to all researches carried out there- see my earlier posting on Stephen Timoshenko).
Though Timoshenko was aware of this theory (Refer his book Theory of Elasticity written with J.N Goodier) he did not pursue it further but Prof. Richardson did (Proceeding of Royal Society of London Vol 210 page 207, 1910), where he solved the stresses in a gravity dam under its own weight and water pressure by finite difference method. As a matter of fact, Olek Zienkeiwicz did his PhD on the same topic under Prof. R.V. Southwell later. Many researchers after this enriched this method of FDM and its application to civil engineering (for instance it is also used in seepage analysis below dams and through its body if made of earth(Taylor), lateral load analysis of piles(Poulos), Analysis of bridge decks and plates(Marcus, Southwell) etc.), it was Runge however, who remained pioneer to apply the method of finite difference for solution of problems related to applied physics, and it still remains a powerful tool irrespective of finite element method in many areas of engineering science especially in the field of computational fluid dynamics.
Another famous work of Runge was that with Martin Kutta of solution of initial value problems (popularly known as Runge-Kutta Method) and remains till date as a powerful numerical tool for solution of problems related to structural dynamics especially when the damping properties are non classical (i.e. the damping matrix do not de-couple on orthogonal transformation and modal analysis technique cannot be applied).  
What type of man was Carle Runge?  
I believe considering his love for histrionics (as Chekov remained one of his favorite author) he developed a very dry sense of humor (Chekovian influence??), where his straight faced comments would often make people around him squeal in laughter. For instance in a particular case, one of his student in Berlin University was finding it difficult to cope in Mathematics and opted out to Literature with poetry as specialization. On hearing this Runge commented with a straight face “It is good of him. I do not think he has adequate imagination to become a mathematician!!
Historically, Gottingen is no exception, in terms of Beer drinking – which is a part of German Culture. Students after classes would sit till late night in pubs drinking beer and working or discussing on their mathematical problems/research at the same time( it has always amazed me it hardly affects their intellectual reflexes) and the general cacophony they would create was borne by all members of the University with an air of genial tolerance ( students also rarely misbehaved- this is one good part of their culture, unlike us, they know exceedingly well to hold their drink).But at some point of time some orthodox group within the university was up against it and wanted to stop this beer drinking business. For this, they decided to organize a seminar on “Evils of beer drinking” and wanted student and faculty both to join this seminar. To this end, they invited all the senior faculties including Runge to attend this seminar. On approaching Runge, when he was explained the purpose of the seminar, Runge with a grave face quipped “ I do not understand why beer is a problem, chemically speaking I see it as a solution”.
Runge was also a very fit and active man, and on his 70th Birthday he entertained his grandchildren by doing handstands. However a few months later he had a heart attack and that became fatal for him.
Hardy Cross (1885-1959):
I would have possibly remained a bachelor if Prof. Hardy Cross was not around! The statement might sound incredulous but nothing could be so nearer to the truth.  
Way back in 1984 after finishing my graduate study, I was working with an engineering consultancy house in Calcutta, where the work experience was though good the pay package was surely not sufficient for me as I had an ailing father to look after and support my younger brother who was a student then. But it did not bother me much, as I was happy with my work (designing Thermal and Nuclear Power Plant) and was hardly saving 100-150 rupees per month.
One day, one of my office colleague got married and after his marriage, a few of us (with whom he was close) were pulling his leg as to where he should go for a honey moon (London, Paris, Timbuktu etc).But my recently married friend said with a very glum and serious face that having blown about 45,000 rupees (majority of which his parents paid) in the marriage ceremony he was completely broke and could not even afford a trip to Digha (a holiday resort very near to Calcutta), as such he was going nowhere (sorry folks, though we were not at all well off then, yet dowry was one thing we never could ever think of).We all sympathized with our colleague but it set me doing some calculations as to how much time I would take to accumulate 45,000 rupees in my bank? To my utter shock!, I found that even with 10% increment in my salary (average) per year, I would be almost 50 years of age before I could have that amount of money in my bank and it was a very optimistic calculation!
This made me realize that I needed money and needed it fast otherwise all my life, I would be struggling perennially to make both ends meet. So what were the options I had?
1) Change my job- but this I was reluctant to do immediately as I was very happy to do what I was doing in my job 2) Earn extra, by working professionally outside my office work – and this looked like the best option for me. (Though I have been out of country now for last two decades but I am told this tradition still remains unabated especially with engineers from consultancy house where the paanwalla sitting near the office still acts the document controller….).
For the information of engineers of present generation as an individual practicing engineer, we did not had any laptops at our disposal then (desktop was out of question being exorbitantly priced), no software like STAAD or excel to aid our computation effort. Only arsenals we had at our disposal was pencil, rubber, A4 size writing pads where we did our calculations and an electronic calculator [ I still remember the model Casio fx(32)] and of course we had Professor Hardy Cross’s method. With such Spartan assets at our disposal- you may not believe, but we could indeed attack almost any conceivable structural problem from a 10 storied building, Conveyor galleries, overhead water tanks, factory sheds, bunkers- anything that you can conjure and the only tool we used was Prof. Cross’s famous Moment Distribution Method (combined with portal and cantilever method for lateral frame analysis).
Young engineers in this forum might feel I am making up stories, but any engineer in this forum (who have worked in 1980s) can testify that this was indeed the design engineering scenario in India then.
Hardy Cross’s moment distribution method has remained one single tool that had dominated the computation in structural engineering like no other method has ever done (not even FEM). If you ask me personally I am yet to come across a method which is so elegant in approach, sound in theory and yet so easy to handle.  
Even today, if in a Staad or Sap output, I find some figures suspicious, I’ll take out the members locally and doing a few cycles of moment distribution if I find that results are not in proximity of 10% of each other, I can tell you with absolute certainty that in 9 out of 10 case there has to be some error in the computer model conceived.
Prof. Hardy Cross was born on 10th February 1885 in Nansemond county of Virginia USA to Thomas Hardy Cross (Not the same man who wrote Far from the madding crowd) and Eleanor Elizabeth Wright (mother). He obtained his bachelor’s degree in civil engineering from MIT and his masters degree from Harvard University in 1911. After a brief stint with Missouri and Pacific rail road he joined the faculty of Brown University where he taught structural mechanics for seven years. In 1921 he joined the faculty of University of Illinois Urbana Champagne (UIUC) as a full professor of structural mechanics. It was in UIUC he developed his famous “Moment distribution method” that became one of the most universally applied tool for structural analysis in the pre computer era. His famous eight page paper “Analysis of continuous frames by distributing fixed end moments” in ASCE led to 144 pages of discussion. No paper in the history of structural engineering ever created so much furor and admiration at the same time.
As a teacher, Prof. Cross was an excellent communicator and would cover most of the question that would come to the mind of the students who attended his lecture-even before they would raise it. This clarity in his delivery, I believe he developed consciously as he was slightly short of hearing and this got worsened with his age. Considering the technology of hearing aid was not so advanced then, students often found it difficult to communicate with him otherwise. In spite of this serious handicap as an educator, he was twice voted the best teacher of the faculty by his students.
(Above information is courtesy Late Subir Nandi,1951 batch of BE College Calcutta and ex chief engineer of Jessop Engineering, who attended Prof Cross’s lectures when he came to Imperial College UK on Sabbatical leave to lecture on his method to graduate students of structural engineering at the behest of Prof. Pippard who was then Dean of Engineering there).
As a teacher, he left an abiding impact in UIUC and under his leadership it became one of the leading institute in research and development of tall buildings a legacy further ameliorated by researchers like F.R.Khan, Mark Fintel and many others..
Prof. Cross died of respiratory ailment in 1959. He and his wife Edith are laid to rest in Ivy Hill Cemetery in Smithfield Virgina.
To be contd…..

Indrajit Chowdhury




This message, including any attachments, may contain confidential and privileged information for the sole use of the intended recipient(s). Review, use, distribution or disclosure by others is strictly prohibited. If you are not the intended recipient, or authorised to receive information on behalf of the recipient, please contact the sender by reply email, and delete all copies of this message. While we have taken reasonable precautions to ensure that this message and any attachments are free from viruses, we cannot guarantee that they are virus free and accept no liability for any damage caused by this message or any attachments. Messages sent or received through our networks may be monitored to ensure compliance with the law, regulation and/or our policies.
This email message has been delivered safely and archived online by Mimecast.
For more information please visit http://www.mimecast.com

Posted via Email
Back to top
View user's profile Send private message
Thankful People
1 user(s) is/are thankful for this post.
vikram.jeet
General Sponsor
General Sponsor


Joined: 26 Jan 2003
Posts: 2212

PostPosted: Fri Oct 12, 2012 7:45 am    Post subject: Outstanding philospohers in Structural Mechanics(4) Reply with quote

Very interesting posting on structural philosophers - - - -

Being passed thru that era of manual structural designing, I can say that it was  
lucky to be a designer of structures performing the frame analysis with Hardy
Cross method (which was further simplified to Two cycle method). The feel of  
structures/structural behavior was automatic .

Compliments to respected Indrajit Chowdhury sahab for yet another piece of  
excellent posting on Structural philosophers describing the contribution of Hardy
Cross. HC method was the best tool of manual design era for analyzing frames.


Kindly keep it up along with your own experiences as structural designer.

with due regds

vikramjeet



Posting from Er Indrajit chowdhary - - - (part)

Young engineers in this forum might feel I am making up stories, but any engineer in this forum (who have worked in 1980s) can testify that this was indeed the design engineering scenario in India then.
Hardy Cross’s moment distribution method has remained one single tool that had dominated the computation in structural engineering like no other method has ever done (not even FEM). If you ask me personally I am yet to come across a method which is so elegant in approach, sound in theory and yet so easy to handle.  
-- ­­

Posted via Email
Back to top
View user's profile Send private message
ibarua
General Sponsor
General Sponsor


Joined: 26 Jan 2003
Posts: 1039

PostPosted: Mon Oct 15, 2012 11:44 am    Post subject: Outstanding philospohers in Structural Mechanics(4) Reply with quote

15th October 2012

Thanks again, Er Chowdhury for your informative posts.


But for Prof. Hardy Cross (1885-1959), I would have changed my profession, for without him it would have never been possible to analyse any real life structures when we had no computers, no electronic calculators and yes, not even mechanical calculators. How far could you go with a slide rule without Hardy Cross? Believe me, Hardy Cross was the one sustained me in those dark Ages.


For you youngsters, here is a breakup of my working life:

1958-1971 -- the slide rule.

1971 -1983 -- electronic calculators, the first one with no memory, the next one with 2 memories and then the Casio-FX32 wth which you could even write simple BASIC programs.


1983 -- the first desktop computer with 16 kb memory and a tape drive; it had a BASIC interpreter and a rudimentary word processor. You had to write a program in BASIC to solve any engineering program.


1985 -- the first IBM PC compatible with two 5.25" floppy drives, 640 KB RAM -- we thought the computer had reached its pinnacle of perfection.

1987 -- my first computer with 1 MB HDD.

The list goes on ................

Indrajit Barua


From: Indrajit_Chowdhury <forum@sefindia.org>
Sent: Fri, 12 Oct 2012 11:05:55
To: general@sefindia.org
Subject: [SEFI] Outstanding philospohers in Structural Mechanics(4)
           Dear Sefians,
In my last two posting I had discussed two philosophers whose work helped structural engineering take great strides in terms of classical analysis (Timoshenko and Rayleigh) .
In the present posting we look into the work of two philosophers who brought a profound change in the analytical philosophy as was prevalent then. It was from this juncture, structural analysis got digressed to numerical analysis whose final outcome is finite element method as we see today. These two gentlemen invariably put structural engineering on a cross road and they are Prof. Carle Runge and Prof. Hardy Cross.
Carle David Tolme Runge (1858-1927):
Who would believe this man’s passion was literature - especially Anton Chekov [Of the famous work Seagull, Caucasian Chalk Circle, Grasshopper…...], and Norwegian Play writer Henrik Ibsen [Distinguished work A Doll’s House, Enemy of the people, Emperor and Galilean….]!!
As a matter of fact, Runge enrolled himself to study literature in University of Munich and then after six weeks changed his mind to turn to physics and mathematics. He had another illustrious son of science as his class mate, none other than Max Planck (of the famed Planck’s constant in quantum mechanics), and they remained friends all their life. In 1877 both went to Berlin to do their Post graduate work while Planck turned to Physics, Runge turned to pure Mathematics, being influenced deeply by Weierstrass’s lectures and came out with a PhD in mathematics from University of Berlin in 1880 where his dissertation topic was differential geometry.
After obtaining his PhD, he joined Faculty of Berlin University and worked under another great mathematician Kronecker (of the famous Kronecker delta function we use in structural dynamics), under whom he worked on a procedure for numerical solution of algebraic equations in which the roots are expressed as infinite series of the rational functions of the coefficients.
In 1904, Felix Klein who was then director of Gottingen University offered Runge a faculty position in the department of applied mathematics, which he accepted and remained therein till he retired in 1923.
In 1908 he published a paper in Z Math Phys (Vol.56 pp 225), wherein he showed how Laplace’s differential equation used in elasticity to define the torsional behavior of a beam be solved by finite difference method(FDM), where a differential equation is ultimately reduced to solution of a system of linear algebraic equations.
Considering the paper was published in German, English speaking world hardly took notice of it except two i) L.F. Richardson from Imperial College of Science and Technology, and ii) Stephen Timoshenko (he is really a hawk eyed guy who rarely missed a good work, moreover considering his close proximity to the faculty of Gottingen through Ludwig Prandtl, he possibly had access to all researches carried out there- see my earlier posting on Stephen Timoshenko).
Though Timoshenko was aware of this theory (Refer his book Theory of Elasticity written with J.N Goodier) he did not pursue it further but Prof. Richardson did (Proceeding of Royal Society of London Vol 210 page 207, 1910), where he solved the stresses in a gravity dam under its own weight and water pressure by finite difference method. As a matter of fact, Olek Zienkeiwicz did his PhD on the same topic under Prof. R.V. Southwell later. Many researchers after this enriched this method of FDM and its application to civil engineering (for instance it is also used in seepage analysis below dams and through its body if made of earth(Taylor), lateral load analysis of piles(Poulos), Analysis of bridge decks and plates(Marcus, Southwell) etc.), it was Runge however, who remained pioneer to apply the method of finite difference for solution of problems related to applied physics, and it still remains a powerful tool irrespective of finite element method in many areas of engineering science especially in the field of computational fluid dynamics.
Another famous work of Runge was that with Martin Kutta of solution of initial value problems (popularly known as Runge-Kutta Method) and remains till date as a powerful numerical tool for solution of problems related to structural dynamics especially when the damping properties are non classical (i.e. the damping matrix do not de-couple on orthogonal transformation and modal analysis technique cannot be applied).
What type of man was Carle Runge?
I believe considering his love for histrionics (as Chekov remained one of his favorite author) he developed a very dry sense of humor (Chekovian influence??), where his straight faced comments would often make people around him squeal in laughter. For instance in a particular case, one of his student in Berlin University was finding it difficult to cope in Mathematics and opted out to Literature with poetry as specialization. On hearing this Runge commented with a straight face “It is good of him. I do not think he has adequate imagination to become a mathematician!!”
Historically, Gottingen is no exception, in terms of Beer drinking – which is a part of German Culture. Students after classes would sit till late night in pubs drinking beer and working or discussing on their mathematical problems/research at the same time( it has always amazed me it hardly affects their intellectual reflexes) and the general cacophony they would create was borne by all members of the University with an air of genial tolerance ( students also rarely misbehaved- this is one good part of their culture, unlike us, they know exceedingly well to hold their drink).But at some point of time some orthodox group within the university was up against it and wanted to stop this beer drinking business. For this, they decided to organize a seminar on “Evils of beer drinking” and wanted student and faculty both to join this seminar. To this end, they invited all the senior faculties including Runge to attend this seminar. On approaching Runge, when he was explained the purpose of the seminar, Runge with a grave face quipped “ I do not understand why beer is a problem, chemically speaking I see it as a solution”.
Runge was also a very fit and active man, and on his 70th Birthday he entertained his grandchildren by doing handstands. However a few months later he had a heart attack and that became fatal for him.
Hardy Cross (1885-1959):
I would have possibly remained a bachelor if Prof. Hardy Cross was not around! The statement might sound incredulous but nothing could be so nearer to the truth.
Way back in 1984 after finishing my graduate study, I was working with an engineering consultancy house in Calcutta, where the work experience was though good the pay package was surely not sufficient for me as I had an ailing father to look after and support my younger brother who was a student then. But it did not bother me much, as I was happy with my work (designing Thermal and Nuclear Power Plant) and was hardly saving 100-150 rupees per month.
One day, one of my office colleague got married and after his marriage, a few of us (with whom he was close) were pulling his leg as to where he should go for a honey moon (London, Paris, Timbuktu etc).But my recently married friend said with a very glum and serious face that having blown about 45,000 rupees (majority of which his parents paid) in the marriage ceremony he was completely broke and could not even afford a trip to Digha (a holiday resort very near to Calcutta), as such he was going nowhere (sorry folks, though we were not at all well off then, yet dowry was one thing we never could ever think of).We all sympathized with our colleague but it set me doing some calculations as to how much time I would take to accumulate 45,000 rupees in my bank? To my utter shock!, I found that even with 10% increment in my salary (average) per year, I would be almost 50 years of age before I could have that amount of money in my bank and it was a very optimistic calculation!
This made me realize that I needed money and needed it fast otherwise all my life, I would be struggling perennially to make both ends meet. So what were the options I had?
1) Change my job- but this I was reluctant to do immediately as I was very happy to do what I was doing in my job 2) Earn extra, by working professionally outside my office work – and this looked like the best option for me. (Though I have been out of country now for last two decades but I am told this tradition still remains unabated especially with engineers from consultancy house where the paanwalla sitting near the office still acts the document controller….).
For the information of engineers of present generation as an individual practicing engineer, we did not had any laptops at our disposal then (desktop was out of question being exorbitantly priced), no software like STAAD or excel to aid our computation effort. Only arsenals we had at our disposal was pencil, rubber, A4 size writing pads where we did our calculations and an electronic calculator [ I still remember the model Casio fx(32)] and of course we had Professor Hardy Cross’s method. With such Spartan assets at our disposal- you may not believe, but we could indeed attack almost any conceivable structural problem from a 10 storied building, Conveyor galleries, overhead water tanks, factory sheds, bunkers- anything that you can conjure and the only tool we used was Prof. Cross’s famous Moment Distribution Method (combined with portal and cantilever method for lateral frame analysis).  
Young engineers in this forum might feel I am making up stories, but any engineer in this forum (who have worked in 1980s) can testify that this was indeed the design engineering scenario in India then.
Hardy Cross’s moment distribution method has remained one single tool that had dominated the computation in structural engineering like no other method has ever done (not even FEM). If you ask me personally I am yet to come across a method which is so elegant in approach, sound in theory and yet so easy to handle.
Even today, if in a Staad or Sap output, I find some figures suspicious, I’ll take out the members locally and doing a few cycles of moment distribution if I find that results are not in proximity of 10% of each other, I can tell you with absolute certainty that in 9 out of 10 case there has to be some error in the computer model conceived.
Prof. Hardy Cross was born on 10th February 1885 in Nansemond county of Virginia USA to Thomas Hardy Cross (Not the same man who wrote Far from the madding crowd) and Eleanor Elizabeth Wright (mother). He obtained his bachelor’s degree in civil engineering from MIT and his masters degree from Harvard University in 1911. After a brief stint with Missouri and Pacific rail road he joined the faculty of Brown University where he taught structural mechanics for seven years. In 1921 he joined the faculty of University of Illinois Urbana Champagne (UIUC) as a full professor of structural mechanics. It was in UIUC he developed his famous “Moment distribution method” that became one of the most universally applied tool for structural analysis in the pre computer era. His famous eight page paper “Analysis of continuous frames by distributing fixed end moments” in ASCE led to 144 pages of discussion. No paper in the history of structural engineering ever created so much furor and admiration at the same time.
As a teacher, Prof. Cross was an excellent communicator and would cover most of the question that would come to the mind of the students who attended his lecture-even before they would raise it. This clarity in his delivery, I believe he developed consciously as he was slightly short of hearing and this got worsened with his age. Considering the technology of hearing aid was not so advanced then, students often found it difficult to communicate with him otherwise. In spite of this serious handicap as an educator, he was twice voted the best teacher of the faculty by his students.
(Above information is courtesy Late Subir Nandi,1951 batch of BE College Calcutta and ex chief engineer of Jessop Engineering, who attended Prof Cross’s lectures when he came to Imperial College UK on Sabbatical leave to lecture on his method to graduate students of structural engineering at the behest of Prof. Pippard who was then Dean of Engineering there).
As a teacher, he left an abiding impact in UIUC and under his leadership it became one of the leading institute in research and development of tall buildings a legacy further ameliorated by researchers like F.R.Khan, Mark Fintel and many others..
Prof. Cross died of respiratory ailment in 1959. He and his wife Edith are laid to rest in Ivy Hill Cemetery in Smithfield Virgina.
To be contd…..

Indrajit Chowdhury




This message, including any attachments, may contain confidential and privileged information for the sole use of the intended recipient(s). Review, use, distribution or disclosure by others is strictly prohibited. If you are not the intended recipient, or authorised to receive information on behalf of the recipient, please contact the sender by reply email, and delete all copies of this message. While we have taken reasonable precautions to ensure that this message and any attachments are free from viruses, we cannot guarantee that they are virus free and accept no liability for any damage caused by this message or any attachments. Messages sent or received through our networks may be monitored to ensure compliance with the law, regulation and/or our policies.
This email message has been delivered safely and archived online by Mimecast.
For more information please visit http://www.mimecast.com

Posted via Email
Back to top
View user's profile Send private message
vikram.jeet
General Sponsor
General Sponsor


Joined: 26 Jan 2003
Posts: 2212

PostPosted: Tue Oct 16, 2012 4:59 am    Post subject: Outstanding philospohers in Structural Mechanics(4) Reply with quote

Respected Inderjeet Barua sir has ,in brief , and chronological order told the  
history of computational aids available with engineers at that time for solving
engineering calculations.

Being much junior to him , but still in the manual design era , the difficulty of calculations
was experienced by us while doing Kani's Method.

Log Tables were also being used for calculations and these were supplied in the  
exams - - - definitely time consuming.

Aristo (costly)/or Deeva(Cheaper) Slide rules were available in market  

Electronic calculators came around mid/late seventies but these were mostly
smuggled items in market at that time , and cost was also very high. These were  
not permitted in exams (thru a note on Que paper ) just to provide equal facilities  
of computations(in form of log tables) to Have's and Have-not's of electronic calculators.

Computer operation was thru FORTRAN LANGUAGE with input data in card punching
to be sent to computer center at IIT Delhi for analysis and output - -as a part of curriculum
in engineering.

best regards

vikramjeet



15th October 2012Thanks again, Er Chowdhury for your informative posts.But for Prof. Hardy Cross (1885-1959), I would have changed my profession, for without him it would have never been possible to analyse any real life structures when we had no computers, no electronic calculators and yes, not even mechanical calculators. How far could you go with a slide rule without Hardy Cross? Believe me, Hardy Cross was the one sustained me in those dark Ages.For you youngsters, here is a breakup of my working life:
1958-1971 -- the slide rule.
1971 -1983 -- electronic calculators, the first one with no memory, the next one with 2 memories and then the Casio-FX32 wth which you could even write simple BASIC programs.
1983 -- the first desktop computer with 16 kb memory and a tape drive; it had a BASIC interpreter and a rudimentary word processor. You had to write a program in BASIC to solve any engineering program.
1985 -- the first IBM PC compatible with two 5.25" floppy drives, 640 KB RAM -- we thought the computer had reached its pinnacle of perfection.
1987 -- my first computer with 1 MB HDD.
The list goes on ................Indrajit Barua
-- ­­

Posted via Email
Back to top
View user's profile Send private message
vinod7
SEFI Member
SEFI Member


Joined: 24 May 2012
Posts: 7

PostPosted: Tue Oct 16, 2012 6:42 am    Post subject: Outstanding philospohers in Structural Mechanics(4) Reply with quote

Dear Members,

Thanks for the postings and really we must be proud because these philosophers has made our way simple and run faster on their roads.

Regards

Vinod Meda

On Mon, Oct 15, 2012 at 8:07 PM, ibarua <forum@sefindia.org (forum@sefindia.org)> wrote:
Quote:
           15th October 2012

Thanks again, Er Chowdhury for your informative posts.


But for Prof. Hardy Cross (1885-1959), I would have changed my profession, for without him it would have never been possible to analyse any real life structures when we had no computers, no electronic calculators and yes, not even mechanical calculators. How far could you go with a slide rule without Hardy Cross? Believe me, Hardy Cross was the one sustained me in those dark Ages.


For you youngsters, here is a breakup of my working life:

1958-1971 -- the slide rule.

1971 -1983 -- electronic calculators, the first one with no memory, the next one with 2 memories and then the Casio-FX32 wth which you could even write simple BASIC programs.


1983 -- the first desktop computer with 16 kb memory and a tape drive; it had a BASIC interpreter and a rudimentary word processor. You had to write a program in BASIC to solve any engineering program.


1985 -- the first IBM PC compatible with two 5.25" floppy drives, 640 KB RAM -- we thought the computer had reached its pinnacle of perfection.

1987 -- my first computer with 1 MB HDD.

The list goes on ................

Indrajit Barua


From: Indrajit_Chowdhury
Sent: Fri, 12 Oct 2012 11:05:55
To: general@sefindia.org (general@sefindia.org)
Subject: [SEFI] Outstanding philospohers in Structural Mechanics(4)
           Dear Sefians,
In my last two posting I had discussed two philosophers whose work helped structural engineering take great strides in terms of classical analysis (Timoshenko and Rayleigh) .
In the present posting we look into the work of two philosophers who brought a profound change in the analytical philosophy as was prevalent then. It was from this juncture, structural analysis got digressed to numerical analysis whose final outcome is finite element method as we see today. These two gentlemen invariably put structural engineering on a cross road and they are Prof. Carle Runge and Prof. Hardy Cross.
Carle David Tolme Runge (1858-1927):

Who would believe this man’s passion was literature - especially Anton Chekov [Of the famous work Seagull, Caucasian Chalk Circle, Grasshopper…...], and Norwegian Play writer Henrik Ibsen [Distinguished work A Doll’s House, Enemy of the people, Emperor and Galilean….]!!
As a matter of fact, Runge enrolled himself to study literature in University of Munich and then after six weeks changed his mind to turn to physics and mathematics. He had another illustrious son of science as his class mate, none other than Max Planck (of the famed Planck’s constant in quantum mechanics), and they remained friends all their life. In 1877 both went to Berlin to do their Post graduate work while Planck turned to Physics, Runge turned to pure Mathematics, being influenced deeply by Weierstrass’s lectures and came out with a PhD in mathematics from University of Berlin in 1880 where his dissertation topic was differential geometry.
After obtaining his PhD, he joined Faculty of Berlin University and worked under another great mathematician Kronecker (of the famous Kronecker delta function we use in structural dynamics), under whom he worked on a procedure for numerical solution of algebraic equations in which the roots are expressed as infinite series of the rational functions of the coefficients.
In 1904, Felix Klein who was then director of Gottingen University offered Runge a faculty position in the department of applied mathematics, which he accepted and remained therein till he retired in 1923.

In 1908 he published a paper in Z Math Phys (Vol.56 pp 225), wherein he showed how Laplace’s differential equation used in elasticity to define the torsional behavior of a beam be solved by finite difference method(FDM), where a differential equation is ultimately reduced to solution of a system of linear algebraic equations.
Considering the paper was published in German, English speaking world hardly took notice of it except two i) L.F. Richardson from Imperial College of Science and Technology, and ii) Stephen Timoshenko (he is really a hawk eyed guy who rarely missed a good work, moreover considering his close proximity to the faculty of Gottingen through Ludwig Prandtl, he possibly had access to all researches carried out there- see my earlier posting on Stephen Timoshenko).
Though Timoshenko was aware of this theory (Refer his book Theory of Elasticity written with J.N Goodier) he did not pursue it further but Prof. Richardson did (Proceeding of Royal Society of London Vol 210 page 207, 1910), where he solved the stresses in a gravity dam under its own weight and water pressure by finite difference method. As a matter of fact, Olek Zienkeiwicz did his PhD on the same topic under Prof. R.V. Southwell later. Many researchers after this enriched this method of FDM and its application to civil engineering (for instance it is also used in seepage analysis below dams and through its body if made of earth(Taylor), lateral load analysis of piles(Poulos), Analysis of bridge decks and plates(Marcus, Southwell) etc.), it was Runge however, who remained pioneer to apply the method of finite difference for solution of problems related to applied physics, and it still remains a powerful tool irrespective of finite element method in many areas of engineering science especially in the field of computational fluid dynamics.
Another famous work of Runge was that with Martin Kutta of solution of initial value problems (popularly known as Runge-Kutta Method) and remains till date as a powerful numerical tool for solution of problems related to structural dynamics especially when the damping properties are non classical (i.e. the damping matrix do not de-couple on orthogonal transformation and modal analysis technique cannot be applied).
What type of man was Carle Runge?

I believe considering his love for histrionics (as Chekov remained one of his favorite author) he developed a very dry sense of humor (Chekovian influence??), where his straight faced comments would often make people around him squeal in laughter. For instance in a particular case, one of his student in Berlin University was finding it difficult to cope in Mathematics and opted out to Literature with poetry as specialization. On hearing this Runge commented with a straight face “It is good of him. I do not think he has adequate imagination to become a mathematician!!â€
Historically, Gottingen is no exception, in terms of Beer drinking – which is a part of German Culture. Students after classes would sit till late night in pubs drinking beer and working or discussing on their mathematical problems/research at the same time( it has always amazed me it hardly affects their intellectual reflexes) and the general cacophony they would create was borne by all members of the University with an air of genial tolerance ( students also rarely misbehaved- this is one good part of their culture, unlike us, they know exceedingly well to hold their drink).But at some point of time some orthodox group within the university was up against it and wanted to stop this beer drinking business. For this, they decided to organize a seminar on “Evils of beer drinking†and wanted student and faculty both to join this seminar. To this end, they invited all the senior faculties including Runge to attend this seminar. On approaching Runge, when he was explained the purpose of the seminar, Runge with a grave face quipped “ I do not understand why beer is a problem, chemically speaking I see it as a solution†.
Runge was also a very fit and active man, and on his 70th Birthday he entertained his grandchildren by doing handstands. However a few months later he had a heart attack and that became fatal for him.
Hardy Cross (1885-1959):
I would have possibly remained a bachelor if Prof. Hardy Cross was not around! The statement might sound incredulous but nothing could be so nearer to the truth.
Way back in 1984 after finishing my graduate study, I was working with an engineering consultancy house in Calcutta, where the work experience was though good the pay package was surely not sufficient for me as I had an ailing father to look after and support my younger brother who was a student then. But it did not bother me much, as I was happy with my work (designing Thermal and Nuclear Power Plant) and was hardly saving 100-150 rupees per month.
One day, one of my office colleague got married and after his marriage, a few of us (with whom he was close) were pulling his leg as to where he should go for a honey moon (London, Paris, Timbuktu etc).But my recently married friend said with a very glum and serious face that having blown about 45,000 rupees (majority of which his parents paid) in the marriage ceremony he was completely broke and could not even afford a trip to Digha (a holiday resort very near to Calcutta), as such he was going nowhere (sorry folks, though we were not at all well off then, yet dowry was one thing we never could ever think of).We all sympathized with our colleague but it set me doing some calculations as to how much time I would take to accumulate 45,000 rupees in my bank? To my utter shock!, I found that even with 10% increment in my salary (average) per year, I would be almost 50 years of age before I could have that amount of money in my bank and it was a very optimistic calculation!
This made me realize that I needed money and needed it fast otherwise all my life, I would be struggling perennially to make both ends meet. So what were the options I had?

1) Change my job- but this I was reluctant to do immediately as I was very happy to do what I was doing in my job 2) Earn extra, by working professionally outside my office work – and this looked like the best option for me. (Though I have been out of country now for last two decades but I am told this tradition still remains unabated especially with engineers from consultancy house where the paanwalla sitting near the office still acts the document controller….).
For the information of engineers of present generation as an individual practicing engineer, we did not had any laptops at our disposal then (desktop was out of question being exorbitantly priced), no software like STAAD or excel to aid our computation effort. Only arsenals we had at our disposal was pencil, rubber, A4 size writing pads where we did our calculations and an electronic calculator [ I still remember the model Casio fx(32)] and of course we had Professor Hardy Cross’s method. With such Spartan assets at our disposal- you may not believe, but we could indeed attack almost any conceivable structural problem from a 10 storied building, Conveyor galleries, overhead water tanks, factory sheds, bunkers- anything that you can conjure and the only tool we used was Prof. Cross’s famous Moment Distribution Method (combined with portal and cantilever method for lateral frame analysis).
Young engineers in this forum might feel I am making up stories, but any engineer in this forum (who have worked in 1980s) can testify that this was indeed the design engineering scenario in India then.

Hardy Cross’s moment distribution method has remained one single tool that had dominated the computation in structural engineering like no other method has ever done (not even FEM). If you ask me personally I am yet to come across a method which is so elegant in approach, sound in theory and yet so easy to handle.
Even today, if in a Staad or Sap output, I find some figures suspicious, I’ll take out the members locally and doing a few cycles of moment distribution if I find that results are not in proximity of 10% of each other, I can tell you with absolute certainty that in 9 out of 10 case there has to be some error in the computer model conceived.
Prof. Hardy Cross was born on 10th February 1885 in Nansemond county of Virginia USA to Thomas Hardy Cross (Not the same man who wrote Far from the madding crowd) and Eleanor Elizabeth Wright (mother). He obtained his bachelor’s degree in civil engineering from MIT and his masters degree from Harvard University in 1911. After a brief stint with Missouri and Pacific rail road he joined the faculty of Brown University where he taught structural mechanics for seven years. In 1921 he joined the faculty of University of Illinois Urbana Champagne (UIUC) as a full professor of structural mechanics. It was in UIUC he developed his famous “Moment distribution method†that became one of the most universally applied tool for structural analysis in the pre computer era. His famous eight page paper “Analysis of continuous frames by distributing fixed end moments†in ASCE led to 144 pages of discussion. No paper in the history of structural engineering ever created so much furor and admiration at the same time.
As a teacher, Prof. Cross was an excellent communicator and would cover most of the question that would come to the mind of the students who attended his lecture-even before they would raise it. This clarity in his delivery, I believe he developed consciously as he was slightly short of hearing and this got worsened with his age. Considering the technology of hearing aid was not so advanced then, students often found it difficult to communicate with him otherwise. In spite of this serious handicap as an educator, he was twice voted the best teacher of the faculty by his students.

(Above information is courtesy Late Subir Nandi,1951 batch of BE College Calcutta and ex chief engineer of Jessop Engineering, who attended Prof Cross’s lectures when he came to Imperial College UK on Sabbatical leave to lecture on his method to graduate students of structural engineering at the behest of Prof. Pippard who was then Dean of Engineering there).
As a teacher, he left an abiding impact in UIUC and under his leadership it became one of the leading institute in research and development of tall buildings a legacy further ameliorated by researchers like F.R.Khan, Mark Fintel and many others..
Prof. Cross died of respiratory ailment in 1959. He and his wife Edith are laid to rest in Ivy Hill Cemetery in Smithfield Virgina.

To be contd…..

Indrajit Chowdhury




This message, including any attachments, may contain confidential and privileged information for the sole use of the intended recipient(s). Review, use, distribution or disclosure by others is strictly prohibited. If you are not the intended recipient, or authorised to receive information on behalf of the recipient, please contact the sender by reply email, and delete all copies of this message. While we have taken reasonable precautions to ensure that this message and any attachments are free from viruses, we cannot guarantee that they are virus free and accept no liability for any damage caused by this message or any attachments. Messages sent or received through our networks may be monitored to ensure compliance with the law, regulation and/or our policies.
This email message has been delivered safely and archived online by Mimecast.
For more information please visit http://www.mimecast.com
     




     



Posted via Email
Back to top
View user's profile Send private message
SANGEETA WIJ
...
...


Joined: 27 Jun 2012
Posts: 56

PostPosted: Tue Oct 16, 2012 11:42 am    Post subject: Outstanding philospohers in Structural Mechanics(4) Reply with quote

Dear Mr Indrajit Chowdhury

I have recently got connected with SEFI again, and I am really impressed with your all your postings on the Outstanding philosophers in Structural Mechanics and it”s indeed a treasure trove. I am sure my friends like Manoj Mittal and Vipul in IAStructE are watching too and would love to lap it up for their Newsletter, of course with your permission.
I would like to seek your experience/opinion on using Concrete Transfer Girders in a Multi Storeyed Housing with many Residential Towers and where Architects do not want the tower columns to carry through to the basements, to give them more parking advantage. The basements are being planned with a rectangular grid of about 8m x 8m while the towers are aligned following a semicircular shape in plan. Do the basements also need to follow the 45m rule for expansion joints?
Best regards and thanks
Sangeeta Wij

From: Indrajit_Chowdhury [mailto:forum@sefindia.org]
Sent: 12 October 2012 11:05
To: general@sefindia.org
Subject: [SEFI] Outstanding philospohers in Structural Mechanics(4)



Dear Sefians,
In my last two posting I had discussed two philosophers whose work helped structural engineering take great strides in terms of classical analysis (Timoshenko and Rayleigh) .
In the present posting we look into the work of two philosophers who brought a profound change in the analytical philosophy as was prevalent then. It was from this juncture, structural analysis got digressed to numerical analysis whose final outcome is finite element method as we see today. These two gentlemen invariably put structural engineering on a cross road and they are Prof. Carle Runge and Prof. Hardy Cross.
Carle David Tolme Runge (1858-1927):
Who would believe this man’s passion was literature - especially Anton Chekov [Of the famous work Seagull, Caucasian Chalk Circle, Grasshopper…...], and Norwegian Play writer Henrik Ibsen [Distinguished work A Doll’s House, Enemy of the people, Emperor and Galilean….]!!
As a matter of fact, Runge enrolled himself to study literature in University of Munich and then after six weeks changed his mind to turn to physics and mathematics. He had another illustrious son of science as his class mate, none other than Max Planck (of the famed Planck’s constant in quantum mechanics), and they remained friends all their life. In 1877 both went to Berlin to do their Post graduate work while Planck turned to Physics, Runge turned to pure Mathematics, being influenced deeply by Weierstrass’s lectures and came out with a PhD in mathematics from University of Berlin in 1880 where his dissertation topic was differential geometry.
After obtaining his PhD, he joined Faculty of Berlin University and worked under another great mathematician Kronecker (of the famous Kronecker delta function we use in structural dynamics), under whom he worked on a procedure for numerical solution of algebraic equations in which the roots are expressed as infinite series of the rational functions of the coefficients.
In 1904, Felix Klein who was then director of Gottingen University offered Runge a faculty position in the department of applied mathematics, which he accepted and remained therein till he retired in 1923.
In 1908 he published a paper in Z Math Phys (Vol.56 pp 225), wherein he showed how Laplace’s differential equation used in elasticity to define the torsional behavior of a beam be solved by finite difference method(FDM), where a differential equation is ultimately reduced to solution of a system of linear algebraic equations.
Considering the paper was published in German, English speaking world hardly took notice of it except two i) L.F. Richardson from Imperial College of Science and Technology, and ii) Stephen Timoshenko (he is really a hawk eyed guy who rarely missed a good work, moreover considering his close proximity to the faculty of Gottingen through Ludwig Prandtl, he possibly had access to all researches carried out there- see my earlier posting on Stephen Timoshenko).
Though Timoshenko was aware of this theory (Refer his book Theory of Elasticity written with J.N Goodier) he did not pursue it further but Prof. Richardson did (Proceeding of Royal Society of London Vol 210 page 207, 1910), where he solved the stresses in a gravity dam under its own weight and water pressure by finite difference method. As a matter of fact, Olek Zienkeiwicz did his PhD on the same topic under Prof. R.V. Southwell later. Many researchers after this enriched this method of FDM and its application to civil engineering (for instance it is also used in seepage analysis below dams and through its body if made of earth(Taylor), lateral load analysis of piles(Poulos), Analysis of bridge decks and plates(Marcus, Southwell) etc.), it was Runge however, who remained pioneer to apply the method of finite difference for solution of problems related to applied physics, and it still remains a powerful tool irrespective of finite element method in many areas of engineering science especially in the field of computational fluid dynamics.
Another famous work of Runge was that with Martin Kutta of solution of initial value problems (popularly known as Runge-Kutta Method) and remains till date as a powerful numerical tool for solution of problems related to structural dynamics especially when the damping properties are non classical (i.e. the damping matrix do not de-couple on orthogonal transformation and modal analysis technique cannot be applied).
What type of man was Carle Runge?
I believe considering his love for histrionics (as Chekov remained one of his favorite author) he developed a very dry sense of humor (Chekovian influence??), where his straight faced comments would often make people around him squeal in laughter. For instance in a particular case, one of his student in Berlin University was finding it difficult to cope in Mathematics and opted out to Literature with poetry as specialization. On hearing this Runge commented with a straight face “It is good of him. I do not think he has adequate imagination to become a mathematician!!
Historically, Gottingen is no exception, in terms of Beer drinking – which is a part of German Culture. Students after classes would sit till late night in pubs drinking beer and working or discussing on their mathematical problems/research at the same time( it has always amazed me it hardly affects their intellectual reflexes) and the general cacophony they would create was borne by all members of the University with an air of genial tolerance ( students also rarely misbehaved- this is one good part of their culture, unlike us, they know exceedingly well to hold their drink).But at some point of time some orthodox group within the university was up against it and wanted to stop this beer drinking business. For this, they decided to organize a seminar on “Evils of beer drinking” and wanted student and faculty both to join this seminar. To this end, they invited all the senior faculties including Runge to attend this seminar. On approaching Runge, when he was explained the purpose of the seminar, Runge with a grave face quipped “ I do not understand why beer is a problem, chemically speaking I see it as a solution”.
Runge was also a very fit and active man, and on his 70th Birthday he entertained his grandchildren by doing handstands. However a few months later he had a heart attack and that became fatal for him.
Hardy Cross (1885-1959):
I would have possibly remained a bachelor if Prof. Hardy Cross was not around! The statement might sound incredulous but nothing could be so nearer to the truth.
Way back in 1984 after finishing my graduate study, I was working with an engineering consultancy house in Calcutta, where the work experience was though good the pay package was surely not sufficient for me as I had an ailing father to look after and support my younger brother who was a student then. But it did not bother me much, as I was happy with my work (designing Thermal and Nuclear Power Plant) and was hardly saving 100-150 rupees per month.
One day, one of my office colleague got married and after his marriage, a few of us (with whom he was close) were pulling his leg as to where he should go for a honey moon (London, Paris, Timbuktu etc).But my recently married friend said with a very glum and serious face that having blown about 45,000 rupees (majority of which his parents paid) in the marriage ceremony he was completely broke and could not even afford a trip to Digha (a holiday resort very near to Calcutta), as such he was going nowhere (sorry folks, though we were not at all well off then, yet dowry was one thing we never could ever think of).We all sympathized with our colleague but it set me doing some calculations as to how much time I would take to accumulate 45,000 rupees in my bank? To my utter shock!, I found that even with 10% increment in my salary (average) per year, I would be almost 50 years of age before I could have that amount of money in my bank and it was a very optimistic calculation!
This made me realize that I needed money and needed it fast otherwise all my life, I would be struggling perennially to make both ends meet. So what were the options I had?
1) Change my job- but this I was reluctant to do immediately as I was very happy to do what I was doing in my job 2) Earn extra, by working professionally outside my office work – and this looked like the best option for me. (Though I have been out of country now for last two decades but I am told this tradition still remains unabated especially with engineers from consultancy house where the paanwalla sitting near the office still acts the document controller….).
For the information of engineers of present generation as an individual practicing engineer, we did not had any laptops at our disposal then (desktop was out of question being exorbitantly priced), no software like STAAD or excel to aid our computation effort. Only arsenals we had at our disposal was pencil, rubber, A4 size writing pads where we did our calculations and an electronic calculator [ I still remember the model Casio fx(32)] and of course we had Professor Hardy Cross’s method. With such Spartan assets at our disposal- you may not believe, but we could indeed attack almost any conceivable structural problem from a 10 storied building, Conveyor galleries, overhead water tanks, factory sheds, bunkers- anything that you can conjure and the only tool we used was Prof. Cross’s famous Moment Distribution Method (combined with portal and cantilever method for lateral frame analysis).
Young engineers in this forum might feel I am making up stories, but any engineer in this forum (who have worked in 1980s) can testify that this was indeed the design engineering scenario in India then.
Hardy Cross’s moment distribution method has remained one single tool that had dominated the computation in structural engineering like no other method has ever done (not even FEM). If you ask me personally I am yet to come across a method which is so elegant in approach, sound in theory and yet so easy to handle.
Even today, if in a Staad or Sap output, I find some figures suspicious, I’ll take out the members locally and doing a few cycles of moment distribution if I find that results are not in proximity of 10% of each other, I can tell you with absolute certainty that in 9 out of 10 case there has to be some error in the computer model conceived.
Prof. Hardy Cross was born on 10th February 1885 in Nansemond county of Virginia USA to Thomas Hardy Cross (Not the same man who wrote Far from the madding crowd) and Eleanor Elizabeth Wright (mother). He obtained his bachelor’s degree in civil engineering from MIT and his masters degree from Harvard University in 1911. After a brief stint with Missouri and Pacific rail road he joined the faculty of Brown University where he taught structural mechanics for seven years. In 1921 he joined the faculty of University of Illinois Urbana Champagne (UIUC) as a full professor of structural mechanics. It was in UIUC he developed his famous “Moment distribution method” that became one of the most universally applied tool for structural analysis in the pre computer era. His famous eight page paper “Analysis of continuous frames by distributing fixed end moments” in ASCE led to 144 pages of discussion. No paper in the history of structural engineering ever created so much furor and admiration at the same time.
As a teacher, Prof. Cross was an excellent communicator and would cover most of the question that would come to the mind of the students who attended his lecture-even before they would raise it. This clarity in his delivery, I believe he developed consciously as he was slightly short of hearing and this got worsened with his age. Considering the technology of hearing aid was not so advanced then, students often found it difficult to communicate with him otherwise. In spite of this serious handicap as an educator, he was twice voted the best teacher of the faculty by his students.
(Above information is courtesy Late Subir Nandi,1951 batch of BE College Calcutta and ex chief engineer of Jessop Engineering, who attended Prof Cross’s lectures when he came to Imperial College UK on Sabbatical leave to lecture on his method to graduate students of structural engineering at the behest of Prof. Pippard who was then Dean of Engineering there).
As a teacher, he left an abiding impact in UIUC and under his leadership it became one of the leading institute in research and development of tall buildings a legacy further ameliorated by researchers like F.R.Khan, Mark Fintel and many others..
Prof. Cross died of respiratory ailment in 1959. He and his wife Edith are laid to rest in Ivy Hill Cemetery in Smithfield Virgina.
To be contd…..

Indrajit Chowdhury




This message, including any attachments, may contain confidential and privileged information for the sole use of the intended recipient(s). Review, use, distribution or disclosure by others is strictly prohibited. If you are not the intended recipient, or authorised to receive information on behalf of the recipient, please contact the sender by reply email, and delete all copies of this message. While we have taken reasonable precautions to ensure that this message and any attachments are free from viruses, we cannot guarantee that they are virus free and accept no liability for any damage caused by this message or any attachments. Messages sent or received through our networks may be monitored to ensure compliance with the law, regulation and/or our policies.
This email message has been delivered safely and archived online by Mimecast.
For more information please visit http://www.mimecast.com

Posted via Email



~WRD162.jpg
 Description:
 Filesize:  823 Bytes
 Viewed:  575 Time(s)

~WRD162.jpg


Back to top
View user's profile Send private message
suraj
General Sponsor
General Sponsor


Joined: 17 Apr 2008
Posts: 1980
Location: NCR Faridabad, E mail suraj_engineer@yahoo.co.uk

PostPosted: Mon Oct 29, 2012 11:15 am    Post subject: Kani's Rotation Contribution Method Reply with quote

Dear Eng Indrajit Chowdhury Sahib
What is your experience regarding Kani's method?
Does it help?

_________________
Thanks & Warm Regards
IntPE(India)Suraj Singh FIE Civil
Engineering & Arbitration

Back to top
View user's profile Send private message Visit poster's website
Indrajit_Chowdhury
Bronze Sponsor
Bronze Sponsor


Joined: 06 Jul 2010
Posts: 26

PostPosted: Mon Oct 29, 2012 11:26 am    Post subject: Reply with quote

Dera Er. Singh,

Other than Hardy Cross's method Kani's method is also used by many for frame analysis, but I peronally find it more laborious than moment distribution and possibly so do many.

Kani'ws method is  also a numerical method and no doubt an important one too, but Prof. Hardy indeed remains pioneer on this issue.

There is also another numerical technique called Takabeya's method(named after Fukuhawa Takabeya), that is popular in Japan but not used much out side their country.

If one observes one would see these are all a derivatiove of Hardy cross's principle in one way or other.

Thanks

IC
Back to top
View user's profile Send private message
SANGEETA WIJ
...
...


Joined: 27 Jun 2012
Posts: 56

PostPosted: Mon Oct 29, 2012 3:49 pm    Post subject: Outstanding philospohers in Structural Mechanics(4) Reply with quote

Hi ICHope you remember me.I work with Prime Group at Gurgaon and would like to stay in touch.Best regardsSangeeta WijThanksWith best regardsSangeeta WijManaging DirectorPrime SD Engg. Consultants Ltd.Regd. Office :Prime Group Building, 11/5B, Pusa Road, New Delhi – 110005Ph.: +91-11-41 888 999 (30 Lines), 41 888 888, 2576 2562-64, 2576 2552-53Fax : +91-11-2575 5815, 2582 1623, Mob.: +91 -9811776210E-mail : sangeetawij@prime-sdec.com, sangeeta@sdclonline.comWebsite : www.prime-sdec.com-
From: "Indrajit_Chowdhury" <forum@sefindia.org>
Date: Mon, 29 Oct 2012 16:56:21 +0530
To: <general@sefindia.org>
ReplyTo: general@sefindia.org
Subject: [SEFI] Re: Outstanding philospohers in Structural Mechanics(4)

     Dera Er. Singh,  Other than Hardy Cross's method Kani's method is also used by many for frame analysis, but I peronally find it more laborious than moment distribution and possibly so do many.  Kani'ws method is also a numerical method and no doubt an important one too, but Prof. Hardy indeed remains pioneer on this issue.  There is also another numerical technique called Takabeya's method(named after Fukuhawa Takabeya), that is popular in Japan but not used much out side their country.  If one observes one would see these are all a derivatiove of Hardy cross's principle in one way or other.  Thanks  IC
        --

Posted via Email
Back to top
View user's profile Send private message
cckeshav
SEFI Regulars
SEFI Regulars


Joined: 28 Jun 2010
Posts: 35

PostPosted: Tue Oct 30, 2012 5:27 am    Post subject: Outstanding philospohers in Structural Mechanics(4) Reply with quote

Dear All.

Hardy Cross's Moment Distribution method needs multiple sway moment analyses to compute moments in unsymmetrical frames. However, in Kani's method the solution can be obtained in one analysis.

C.Channakeshava


Subject: [SEFI] Re: Outstanding philospohers in Structural Mechanics(4)
From: forum@sefindia.org
Date: Mon, 29 Oct 2012 16:56:21 +0530
To: general@sefindia.org

           Dera Er. Singh,

Other than Hardy Cross's method Kani's method is also used by many for frame analysis, but I peronally find it more laborious than moment distribution and possibly so do many.

Kani'ws method is also a numerical method and no doubt an important one too, but Prof. Hardy indeed remains pioneer on this issue.

There is also another numerical technique called Takabeya's method(named after Fukuhawa Takabeya), that is popular in Japan but not used much out side their country.

If one observes one would see these are all a derivatiove of Hardy cross's principle in one way or other.

Thanks

IC

Posted via Email
Back to top
View user's profile Send private message
Display posts from previous:   
Post new topicReply to topic Thank Post    www.sefindia.org Forum Index -> SEFI General Discussion All times are GMT
Goto page 1, 2  Next
Page 1 of 2

 

 
Jump to:  
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
You cannot attach files in this forum
You can download files in this forum


© 2003, 2008 SEFINDIA, Indian Domain Registration
Publishing or acceptance of an advertisement is neither a guarantee nor endorsement of the advertiser's product or service. advertisement policy