Journal of Engineering Mechanics, To release Peer Reviewed Paper WTC Collapses

Keith Seffen has written a paper for all you math geeks and engineering nerds to read. Please let me know what 90% of those calcualtions mean!!

Griff, Val... I am sure you two will be all over this one!




winterpatriot.pbwiki.com...

[edit on 10-11-2007 by CaptainObvious]

Hi CO,

Started reading already...thanks for the link. So that we can make sure this discussion doesn't get muddled from the get-go, this paper deals with POST-initiation (i.e. post-collapse onset) and the global collapse that followed.



[edit on 11-10-2007 by Valhall]

to my mind (because i have a bias about the collapse)
Page 8 of your PDF link sorta spells it out.

we have reports that columns/beams were thrown up tp 400 ft
from the footprint of the collapse...page 8 allows us to figure out how
that might occur and it also sheds light on how all the concrete floors were pulverized into dust. (it seems columns could & did start destruction to the 2nd or 3rd floor levels below the collapsing floor, at each given moment)

additionally, this paper, although it does not prove the absence of pre-set explosives....it does set the model that fast moving 747 type of aircraft
crashing into the buildings could cause the universal collapses of the twin towers...ain't no covert activities needed- - our buildings are all suspect
of universal failure if/when attacked...we have been fed a load of false
security standards


good discovery

[edit on 10-11-2007 by St Udio]

Now this is what I personally like to see. Peer-reviewed papers used for support and rebuttal of an argument. Good find, Cap'n. Starred and Flagged. I will be very disappointed if this thread goes unnoticed.

I'm sorry, CO, but they have over-simplified the approach. They are analyzing perimeter (and core) columns as if they are 12' long columns for each story. While I'm sure this has been peer reviewed, and I'm sure it passed muster as "accurate in approach for the assumptions made", the problem is the "assumptions made" are flawed and over-simplified.

The perimeter columns were a lattice work of three columns, spanning three floors, with each column about 3' from the next. At each floor a spandrel plate connected the three columns to form what is called a "Vierendeel Truss".

You cannot analyze individual columns on the perimeter walls. The Vierendeel Truss is an indeterminate structure that cannot be modeled with a simplistic approach as is taken in this paper. You must take into account the construction and the effects it has on the behavior of the constituent components. To calculate a slenderness ratio based on a single perimeter column of 12' length and then calculate buckling of that singular column is - well - ludicrous.

If you would like to understand the benefits of a Vierendeel Truss, read here:

ntrs.nasa.gov...

If you would like to see the behavior of a heavily damaged building near the WTC complex that had 17 stories of it's Vierendeel Truss perimeter wall removed due to falling debris from WTC 2, and has similar construction, but remained standing, read here:

mceer.buffalo.edu...

And if you would like to read what FEMA has to say about the effects of the Vierendeel Truss action on the towers, read here:

www.fema.gov...

But I'll quote a couple of important sections for you:

Most of the load supported by the failed columns is believed to have transferred to adjacent perimeter columns through Vierendeel behavior of the exterior wall frame. Preliminary structural analyses of similar damage to WTC 2 suggests that axial load demands on columns immediately adjacent to the destroyed columns may have increased by as much as a factor of 6 relative to the load state prior to aircraft impact. However, these exterior columns appear to have had substantial overstrength for gravity loads.

The analysis indicates that most of the loads initially carried by the damaged exterior columns were transferred by Vierendeel truss action to the remaining exterior columns immediately adjacent to the impact area. If the floors at this level are assumed to remain intact and capable of providing lateral support to the columns, this raised the utilization ratio for the most heavily loaded column immediately adjacent to the damage area to approximately a value of 1.0. At a value of 1.0, columns would lose stiffness and shift load to adjacent columns. Based on this analysis, it appears that the structure had significant remaining margin against collapse. However, this analysis does not consider damage to the building core, which was likely significant. Columns located further from the damage area are less severely impacted, and columns located only 20 feet away from the damaged area experience almost no increase in demand at all.

[edit on 11-10-2007 by Valhall]

In addition, they have assumed the failure scenario that one 12' column fails and then falls en masse onto the floor below it thereby causing a dynamic loading that can cause failure in the next 12' column even though the static load strength of the 12' columns on the floor below it may not be overcome. (Even though there weren't any 12' columns.)

Well, it would be pretty hard for a column that spans 3 stories, even if it does fail in buckling, to just fall over on the floor, bein's it's got about 20 more feet of column below it you have to account for. In other words, it would have to be falling on it's self, or breaking off every 12', whatever you want to play with there.

And, as video evidence shows, the perimeter columns weren't falling on the floor below them, they were peeling away from the building.

[edit on 11-10-2007 by Valhall]

reply to post by CaptainObvious


I'll tell you what:
Go build a tower in your living room. You can make it out of pizza boxes, LEGO blocks or anything else you want to ..... hell, you can even build it out of a pile of pancakes if you want. You can use Genga blocks too, or Popsicle sticks or a bunch of paper cups glued together. Build it out of ANYTHING your heart desires.

But make sure the tower is 5 times as high as it is wide at the base. So if the tower is 1 foot wide at the base it must be 5 foot tall.

Then set fire to the top about where the planes would have hit, you can use gasoline or jet fuel for this if you want. You can also throw a rock at it to simulate a plane crash. And watch it.

See if you can re-create a progressive collapse as it happened on 9/11. I mean that the top floors collapse down vertically onto the floors below and destructing every section below all the way to the ground. See if some LEGO block will get thrown sideways from the collapse. See if any of the steel components get melted and still can be found in the rubble of your tower the next day.

What you will find is that the progressive collapse or the pancake collapse are both completely impossible to reproduce. Only on that day did 3 buildings fall to the ground straight down onto themselves at the speed of free fall with molten steel found in the basements.

No other time in history has this ever happened, but if it happened 3 times on that day, you surely will be able to reproduce this "progressive collapse" once again?

And BTW, your paper, does it say anything about the existence of the molten steel found in the basements of all 3 buildings?
I bet like every other oh-fishy-all story, the guy pretends that no such steel ever existed.

Cheers,
PepeLapiu

Originally posted by CaptainObvious
Keith Seffen has written a paper for all you math geeks and engineering nerds to read. Please let me know what 90% of those calcualtions mean!!

Griff, Val... I am sure you two will be all over this one!

winterpatriot.pbwiki.com...

Show me any evidence that this paper was peer reviewed, any evidence at all!

Thanks CO for this post and thanks to Valhall for your critique of the paper.
Pepe mentioned proof of the Peer review and I'll admit I could only get through four pages of it.I'd be interested in knowing the Peers who reviewed this paper.
I lost interest and the paper lost credibility when it started comparing the WTC collapse to a balloon and a plastic pipeline.Neither one of these analogies has relevance to a 110 story steel structure collapsing at near free fall speed.
It appears to tow the official story in my opinion,which I don't buy.
I look forward to reading more analysis from the math and engineer people here.
You get a thumbs up from me for the post

reply to post by Valhall


Hi Val ~

Don't say your sorry to me! I wasn't involved in the peer review process. If you want my 2 cents, wirte to the author of this paper. I believe his contact info is on his paper. Also write to the magazine that is publishing this. I wold love to see what their response would be.

Thank VAl for your information.

Originally posted by PepeLapew


I'll tell you what:
Go build a tower in your living room. You can make it out of pizza boxes, LEGO blocks or anything else you want to ..... hell, you can even build it out of a pile of pancakes if you want.......
Then set fire to the top about where the planes would have hit, you can use gasoline or jet fuel for this if you want. You can also throw a rock at it to simulate a plane crash. And watch it.



What you will find is that the progressive collapse or the pancake collapse are both completely impossible to reproduce. Only on that day did 3 buildings fall to the ground straight down onto themselves at the speed of free fall with molten steel found in the basements.

No other time in history has this ever happened, but if it happened 3 times on that day, you surely will be able to reproduce this "progressive collapse" once again?

And BTW, your paper, does it say anything about the existence of the molten steel found in the basements of all 3 buildings?
I bet like every other oh-fishy-all story, the guy pretends that no such steel ever existed.

Cheers,
PepeLapiu

Your kidding right? I can't WAIT to see this movie you are creating. Are you going to be lighting pizza boxes on fire in your basement?

"Your" paper?? I didn't write it.... hell I admitted to not understanding 90% of it. I posted it for those who would find in interesting and to discuss it in here.


There is no proof what so ever that there was molten "STEEL" in the basements, nor did the buildings fall at free fall speeds. Your logic on this is about 3 years behind all the other truthers.

Pepe, i suggest you write the magazine where this is to be published, and state your concerns to them.

[edit on 10-11-2007 by CaptainObvious]

reply to post by CaptainObvious


Molten Steel

Firefighters Story

Another one

This is in reply to your no proof of molten steel CO.While I don't consider it 100% you can agree that there is at least evidence given the links provided.
The WTC 1,2 & 7 may have not fallen at exact free fall speed but it was closer to that than any other explanation/model/excuse.
No derail intended.

reply to post by citizen truth


First of all, there has been ZERO analyisis of the molten material that was reported to be seen at GZ. To say that is it steel is not appropriate. IF you do happen to find some reported testing of this material, please post it.

I'm not here to debate the collapse, I leave that for the engineers and others with that background.

The OP shows a link to a peer reviewed paper. I encourage you to find fault with this paper and notify the magazine and the author..and of coarse discuss it here.

CO,

Do you understand the problem with his "simple analysis"? He is treating the columns as discrete 12' columns that have endpoints at each floor. Then he is saying that all the columns on one floor are falling onto the floor when they fail and contributing to the dynamic loading of that floor to assist in failing it and so it goes on down floor by floor. But the columns were 30-36' long...they spanned three floors. And for the perimeter columns that was a Vierendeel truss configuration spanning three floors.

To be quite honest, I am very surprised this is being published.

reply to post by PepeLapew


Pepe ~

I am still looking into your request. I do know it is being released as such. In the mean time, I will offer Dr.Keith Seffen's credentials and some of his work just to show you his knowledge. Also there is his contact information.

Keith A. Seffen MA PhD CMath MIMA MAIAA
University Senior Lecturer in Engineering
Fellow of Corpus Christi College
T: +44 (0) 1223 7 64137
F: +44 (0) 1223 3 32662
E: [email protected]

Dr Seffen has general interests in reconfigurable structures, as described in his research page; other pages can be reached from the navigator list on the left - clicking on "home" restores this page. Please feel free to contact him by 'phone or E-mail or in person.

www2.eng.cam.ac.uk...

Biography

Dr Seffen is a University Lecturer in Engineering, specialising in Structures, at Cambridge University Engineering Department (CUED). He is a member of the Civil, Structural and Environmental Engineering Division (Division D). He is an Official Fellow of Corpus Christi College, where he has been a Director of Studies, Tutor and Deputy Senior Tutor. Previously, he was a Lecturer in Smart Structures and Materials in the Department of Mechanical Engineering at UMIST (1999-2001, now part of the University of Manchester) and a Research Associate in the Engineering Design Centre at CUED (1997-1999). His PhD (1993-1997) was performed under the supervision of Prof. Pellegrino in the Deployable Structures Group. Keith Seffen read the Engineering Tripos at Cambridge University (1990-1993) and gained a first class degree. He was born, bred and educated in Northern Ireland.

www2.eng.cam.ac.uk...

Research

ReconStruct
Laboratory for Reconfigurable
Structures Research

Research activities are generally concerned with reconfiguring structural or material form, for synthesising unique, unusual but expeditious properties, to enable, for example, morphing capabilities, large-displacement continuous actuation, ultra-low densities. Click on each of the pictures above for more detail or visit the publications page for specific papers. Dr Seffen is a Chartered Mathematician (CMath), a member of the Institute of Maths and its Applications (IMA) and a member of the American Institute of Aeronautics and Astronautics (AIAA).

www2.eng.cam.ac.uk...

Teaching

Dr Seffen lectures the fourth year modules, Structural Steelwork and Plates and Shells: Theory and Computation. He is also a demonstrator on the Structural Design Course, as well as an examiner throughout the Tripos. Since October 2003, he has been the Director of Studies in Part IA Engineering at Corpus Christi College and he supervises undergraduates in Part IA and IB Structural Mechanics and Mechanics.

www2.eng.cam.ac.uk...

Here is a list of his 10 most recent technical writings

F Xu, T J Lu & K A Seffen, "Effect of Thermal Damage on the Compressive Behaviour of Skin Tissue", (2008) Journal of Mechanics in Medicine and Biology, in press
F Xu, T Wen, T J Lu & K A Seffen, "Skin Biothermomechanics Under Medical Treatments", (2008) Journal of the Mechanical Behaviour of Biomedical Materials, in press
F Xu, T J Lu & K A Seffen, "Characterization of Temperature-Dependent Mechanical Behaviour of Skin tissue", (2008) Engineering Letters, in press
F Xu, T Wen, K A Seffen & T J Lu, "Modelling of Skin Thermal Pain - a Preliminary Study", (2008) Applied Mathematics and Computation, in press
K A Seffen,"Progressive Collapse of the World Trade Centre: a Simple Analysis", (2007) ASCE Journal of Engineering Mechanics, in press
F Xu, T Wen, K A Seffen & T J Lu, "Characterization of Thermomechanical Behaviour of Skin Tissue II. Viscoelastic Behaviour", (2007) IAENG (WCE) International Conference of Systems Biology and Bioengineering (ICSBB'07), 2-4 July 2007, London , UK
F Xu, T Wen, K A Seffen & T J Lu, "Characterization of Thermomechanical Behaviour of Skin Tissue I. Tensile and Compressive Behaviours", (2007) IAENG (WCE) International Conference of Systems Biology and Bioengineering (ICSBB'07), 2-4 July 2007, London , UK
A D Norman, S D Guest & K A Seffen, "Novel Multistable Corrugated Structures", (2007) 48th AIAA/ASME/ASCE/AHS/ ASC Structures, Structural Dynamics and Materials Conference, 23-26 April, Hawaii
K A Seffen, "Performance of a Coiled Coil Piezoelectric Bimorph", (2007) Sensors and Actuators A: Physical, 133(2), pp.486-492, DOI: 10.1016/j.sna.2006.04.016
K A Seffen, "Hierarchical Multi-stable Shapes in Mechanical Memory Metal", (2007) Scripta Materilia, 56(5), pp.417-420

www2.eng.cam.ac.uk...

There is an abundance of information at this website. I just posted some of what was available.

Thanks ~ C.O.

reply to post by Valhall


Valhal ~ I can't speak for him. I think your best bet again, would be to contact him. As you can see above, I have posted his e-mail and his phone number. In addition here is the address to his university:

University of Cambridge, Department of Engineering, Trumpington Street, Cambridge CB2 1PZ

Thanks again Val!

Okay, I sent him this:

Hello Dr. Seffen,

I have been reading your paper Progressive Collapse of the World Trade Centre: a Simple Analysis and I would like to discuss some concerns I have with your approach. While I firmly agree that the dynamic loading of floors after collapse onset played a role in subsequent floor failures, I'm afraid your "simple analysis" is far too simple.

In your paper you treat columns as if they have a length of one floor height (i.e. approx. 12 feet) and have endpoints at each floor. You then go on to apply their full weight (and the dynamic loading associated with that weight falling) to the next floor when they fail. In reality, the columns were three floors in length (approx. 36 feet). So taking a single floor height of 12' on a 36' column, and allowing that 12' to be the top 1/3 of the column length, it becomes problematic to apply the weight of that 12' to the next floor when 2/3's of the column length is still embedded and integral to the structure of the next 2 floors.

And that applies to both the core columns and the perimeter columns, but when stepping out to the perimeter columns the problem becomes even more complex in that the perimeter columns were configured into 3 story Vierendeel trusses of 3 column width with spandrels at each floor. When you get to these trusses on the external walls, it becomes even less realistic to apply a single floor column weight to the floor. In addition, as video evidence of the day shows, the perimeter trusses tended to fall away from the structure, not into it.

In addition to contesting the application of each floor's respective column weights to the next floor failure, the Vierendeel truss configuration on the external walls precludes analyzing individual external columns in a simple buckling analysis as the Vierendeel truss action will cause significant changes to the response of each integrated column, and neighboring truss columns.

Thank you very much for taking the time to read my concerns, and I look forward to hearing back from you on these matters.

Kindest Regards,
, P.E.

[edit on 11-11-2007 by Valhall]

reply to post by Valhall


Val ~

Awesome job. I look forward to his response... and you sharing it with us!

Thanks,

C.O.

gave you a star as well

BTW, CO, I notice he is a member of AIAA, as am I. I will check to see if the paper was submitted for review to that organization, but I have a feeling it wasn't. Most likely it was submitted for review to a group who would have centered on the approach of dynamic loading analysis. That's why I say that while the paper may have been peer reviewed, it doesn't necessarily mean it is of value in discussing what actually happened in the WTC progressive collapse - at least not in entirety. And what I mean by that is if you submit a technical paper to a particular group of specialty, they will review your accuracy of that specialty - not necessarily that your entire approach (say your assumptions) are correct.

This is where we get into the problems of the label "peer reviewed". It can cause the appearance that the paper is sound in all aspects when in fact it may have only been analyzed for certain techniques. From a dynamic loading standpoint, it appears Dr. Seffen's technique is sound - but his assumptions of what occurred are not necessarily (i.e. that each floor had columns with discrete endpoints at top and bottom).

[edit on 11-11-2007 by Valhall]

reply to post by Valhall


Thanks again Val... I learned something today!!!!