CAN NEWTON'S LAWS BE SUSPENDED?

" The official version of 9/11 implies that Newton’s Laws were suspended that day. We challenge all professors, but especially the physics professors to discuss the relevance of Newton’s Laws to 9/11, publicly or privately. "

HM: Newton's laws of motion

       Gravity

Bevin Chu: " With the revelations of Edward Snowden and others, it is increasingly clear that our civil liberties are disappearing.

-------Research 9/11: https://kendoc911.wordpress.com -----

By refusing to expose the lies around such a crucial political event as 9/11, acade- mics encourage this trend. As our civil liberties and freedoms disappear, academic freedom will also disappear.

We are asked to accept 9/11 as the excuse for the loss of such freedoms without questioning.

Consider Newton’s three laws:

1. An external force (such as gravity) is needed to change an object’s velocity.

2. F=MA: An object’s acceleration is directly proportional to the force exerted on it. (When an object falls under the influence of gravity alone and unopposed by any up-ward force, it accelerates at the rate “g,” about 9.8 meters per second squared.In the presence of a resisting force,like a building structure,acceleration in a fall will be less than g.)

HM: This latest sentense is not exactly tue, if also ACCELERATING forces can influ-ense on some falling part of a collapsing constuktion. That was the case for instance with WTC-tower "hats" over the hit and fire area after the core and floors had started to fall inside the house. The floor elements were strongly fixed at the tube elements, and fallaing down before they accelerated the hats fall.It could even fall with greater acceleration than g ("turbo-free fall"...) as happened in one roof line in WTC-7.

"Resisting" and "acceleration" are one and the same phenomenon physically. Resisting is also acceleration, but in opposite direction to actual velocity.

BC: " 3. When two objects collide, each exerts an equal and opposite force upon the other.

(For example, the upper section of a building exerts on the section below it a downward-directed force equal in magnitude and opposite in direction to the upward-directed force that the lower section exerts on the upper section.)

HM: This is tue when the "parts" are in eduilibrium, in rest.

But in that moment when the inner part,core and floors, starts to collapse, this "upper section" ceases to be one part (of a whole), one object, it "breaks" in separate parts which have there own acceleration and independent forces acting on them. The tube walls is the part which falls last.Falling it is under gravitation,under other accelerating downwards loads from floor elements, the falling of which the tube resists because they are on one end fixed to tube "hat".

That way to devide the building to "parts" is inadequate functionally. The functional parts are the tube, the core and the floors.

BC: " NCSTAR 1A, which is the final report of the Collapse of World Trade Center Building 7 by the National Institute of Standards and Technology, part of the US Department of Commerce,concluded that during a significant interval in its collapse on September 11 2001, World Trade Center Building 7 accelerated at the rate g as though nothing was resisting its fall. "


HM: One roof line accelerated more than g. There is nothing "strange, and no Newton´s law is broken.

No part under condideration was in free fall. And no free fall condition was mentioned in NIST report. There was mentioned a "free fall speed" for a point whose acceleration in that moment was more than g.

The acceleration in a free fall condition is measured at the centroid of the falling massive. In other points of the massive can be whatever other acceleration.

 

BC: " In other words, all those steel members that seconds earlier had been holding the building up suddenly withdrew their support and did not slow the collapse at all. "

HM: No, that was not the situation! Not at all!

1. The "main supporting part", the core,fell FIRST. The tube,the only part which you see in videoes,FELL LAST:Otherwise the building could not have fallen on footprints.

2. The core lost its capasity due to the loosing the lateral support from the floors. Fall of two floors dropped the capacity of core columns in 1/9, because the load bearing capacity of a beam is inverse proportional to the quadrat of the length of the beam.

3. The only vertical support for the tube was the tube itself. The tube columns also loosed their capacity due to the fall of the floors inside the building.

4.If there had been large expolosions in the buiding under the strike level,they would have resisted the fall of the hat, pulled it upwards, not accelerated it downwards.


BC: " That could happen only if either:

• the supporting structure was very rapidly removed and the only force on the collapsing building was gravity, or "

• if the structure remained but somehow failed to exert a force opposing the collapsing part of the building. But Newton’s Third Law says that can’t happen.

Thus, the supporting structure must have been removed.
~Courtesy: http://houston911truth.net/NEWTON.pdf "

HM: You do not see the building in your videoes, you see the tube only.

And you see fully the only part which supports the tube: it is the tube itself. No other upwards vertical (resisting) force form the lower part of the building is acting on the upper part (the "hat") of the tube.

-----------------------------------------------

BC: " Key Evidence:

**** Rapid onset of destruction,
https://www.youtube.com/watch. "

HM: You do not see in videoes the onset of destruction. It stated inside building several secons before before you see anything special happening in the tube.
 

BC: " **** Constant acceleration at or near free-fall through what should have been the path of greatest resistance,
https://www.youtube.com/watch… "

HM: The tube which you see in videoes IS NOT THE PART OF GREATIST RESISTANCE (bearing capacity)!

The part of greatisti lod-carrying capastity, the core FELL FIRST!

The pancake theory is principially right, and it is not "revised by NIST later" as the trthere say:

The Truss Failure Theory

Figure 2-20 from FEMA's Building Performance Study gives the impression that floors spanned the entire width of the Towers. The fine print indicates that the illustration depicts only a section of floors spanning the perimeter (left) and core (right). " Tis is between the core and the tube. Only the lowest picture is right. The deformation concetrate to the tube wall.

The truss failure theory, a key ingredient of the better known floor pancake theory, was endorsed by FEMA in its 2002 World Trade Center Building Performance Study . It invites us to imagine the floors assemblies detaching from their connections to the columns of the core and perimeter walls, precipitating a chain reaction of floors falling on one another. Without the lateral support of the floors, the columns, FEMA tells us, buckled and precipitated total building collapse. "

HM: This is true for the towers.

" The truss-failure/pancake theory offered a way around the obvious problem with the column failure theory: the need for all the columns to be heated to 800º C. It offered instead prerequisite conditions that were far less implausible: that trusses holding up the floor slabs were heated to that temperature, and began to experience some combination of expansion and sagging. Floor trusses are much easier to heat because, unlike the columns, they are not well thermally coupled to the rest of the steel structure.

The Truss Failure Theory was was abandoned by NIST's investigation in 2004 because NIST was unable to get floor assemblies to fail as required by the theory. Documentaries that had promoted the truss failure theory became obsolete, and were quietly replaced with updated versions. "

It is not abondoned for the WTC-1 and WTC-2 toers!. It is quite adequte theory.

The essence on the theory is what happens to a floor on which the upper floor or part of it drops. Does it drop also the second floor or not.

In my model that which breaks is one floor element with ten tons load, not the floor truss (when about ten floor elements fall).

THIS MECHANISM IS A PLANNED MECHANISM OF THE COLLAPSE OF WTC-1 AND WTC-2 TOWER AFTER THE REQUIRED FIRE RESISTANCE TIMES FOR THE TOWERS TO FALL WITHOUT MAKING WHOLE MANHATTAN TO TO FALL DOWN IN A DOMINO COLLAPSE EFFECT.


BC; **** Numerous eyewitness accounts of explosions
https://www.youtube.com/watch… "

HM: It is not possible to hear difference between a break of a massive beam from tensile forces with, or wihout exlposion, or some other reason. With technical devices that difference can be made. There was no techical measured results fom expolosions (seismic etc.).

BC: " **** including 118 FDNY personnel,
https://www.youtube.com/watch?v=cZ4dVo5QgYg&feature=youtu.be "

**** Lateral ejection of multi-ton steel framing members distances of 600 feet at more than 60 mph,
https://www.youtube.com/watch… "

HM: This is fully possible from bending, "bow", spring forces.

" **** Mid-air pulverization of 90,000 tons of concrete, and large volumes of expanding pyroclastic-like dust clouds,
https://www.youtube.com/watch… "

HM: Concrete did not pulverize. Somewhat went to sand. Concrete floor elements fell in the five storeys cave unfer the street level.

The pulvers were plaster, and ashes from paper, wood, plastic etc. from the storeys. There was allowed to be load about 400 kg/floor-m^2  from that kind of materials.

BC: " **** Isolated explosive ejections 20 to 60 stories below the “crush zone,”
https://www.youtube.com/watch  "

HM: They are not explosive ejections. They are ejection from air pressure caused by the falling floor elements.

BC; " **** Total destruction and dismemberment of all three buildings, with 220 floors each an acre in size missing from the Twin Towers’ debris pile,
https://www.youtube.com/watch…. "

HM: The debris, for instace concrete, was in the 5 storey caves under the street level.

You think all other people are fully idiots...

BC: " **** Several tons of molten steel/iron found in the debris piles,
https://www.youtube.com/watch…. "

HM: It is not steel. It is aluminum from the aeroplanes and furnitures. Magnesium component has burned.

BC: " **** Evidence of thermite incendiaries on steel beams,
https://www.youtube.com/watch…. "

**** Nanothermite composites and iron microspheres found in WTC dust samples
https://www.youtube.com/watch…
https://www.youtube.com/watch… "

HM: Thermite is not explosive. It is welding material. It can have been used in buildind. Hot aluminium and rust can have had small scale thermite reactions.

-------------------------------------------

BC: " Consider David Chandlers handling of this predicament:

https://www.youtube.com/watch?t=15&v=c1Vc_QjR-2s

Also consider his handling of the collapse of World Trade Center 7 which was not hit by a plane, which collapsed at free fall speed (acceleration of gravity for 2.5 seconds) neatly into it's own footprint in 6.5 seconds.

https://www.youtube.com/watch?v=rP9Qp5QWRMQ "

HM: Its fall time was 16 seconds as I remember, form the fall of first floor elements in the progerssive collapse.

What would have been wrong in exploding WTC-7 form the planned critical column(s) 7 hours after it had started to burn?

-------------------------------------------

BC: " Below are some documentaries that I highly recommend:

9/11:EXPLOSIVE EVIDENCE - THE EXPERTS SPEAK OUT (Final Version 2012)
https://www.youtube.com/watch?v=6xif0jIT_ZM "

HM: Nothing to do with this question.

Architects & Engineers - Solving the Mystery of WTC 7 - AE911Truth.org
https://www.youtube.com/watch?v=hZEvA8BCoBw "

HM: They are bullshit engineers and architects in this question.

BC: " September 11 -- The New Pearl Harbor (FULL)
https://www.youtube.com/watch?v=8DOnAn_PX6M "

HM: Interesting but irrelevant.

BC: " 9/11 Suspects - Explosive Connections (Updated Fixed and Revised) https://www.youtube.com/watch?v=ffs7PkOREEY

David Chandler of Architects & Engineers for 9/11 Truth presents the best short video evidence of 9/11 in this playlist:

https://www.youtube.com/playlist?list=PL206C1F5EDFC83824 "

HM: No interest for a specialist.

-------------------------------------------------
-----HARD FACTS OF 9/11 ------------
-------------------------------------------------
source: https://kendoc911.wordpress.com/category/hard-facts/

9/11 is a topic that is normally frowned upon by others who have never done re-search on the event. When discussing 9/11 to deniers and/or uninformed people, we need to keep things SIMPLE and PRECISE with solid facts that cannot be discredi-ted. In my opinion, the “official story” IS the conspiracy theory that does not stand up to scientific scrutiny. "

HM It is all right. Of course the authorities do not want to give good advice for potential terrorists for new strikes.

This act would have been done by much easier way and less people (for instace fy city guerilla Koivula).

BC: " I have made a list of 24 HARD FACTS about 9/11 that we should mainly focus on to generate awareness and acceptance.People need to know the FACTS!

1) Nano Thermite found in the dust at Ground Zero. Peer reviewed in the Bentham Open Chemical Physics Journal. ‘Thermite Bentham’, “The great thermate debate”, ‘Iron rich spheres’, ‘Limited Metallurgical Examination (FEMA C-13, Appendix C-6)’. ‘Steven Jones’ ‘Niels Harrit’, ‘Mark Basile’, ‘Jon Cole’, ‘Nano Tubes’. "

HM: No interest.Thermite can have been used in weldings. And small scale thermite reactions happened between hot aluminium ahd rust. Thermite is not explosive.

https://en.wikipedia.org/wiki/Thermite

BC: " 2) 2000+ Engineers and Architects support a real independent 9/11 investi-gation. ‘Explosive Evidence’,’Blueprint for Truth’, ‘Toronto Hearings’, ‘Richard Gage’, ‘Kevin Ryan’, ‘ae911truth.org’. "

HM: That kind of investigation is useless.

BC: " 3) The total collapse of WTC 7 in 6.5 seconds at free fall acceleration (NIST admits 2.25 seconds). Larry Silverstein used the term “Pull it”. Steel framed high rise buildings have NEVER totally collapsed from fire or structural damage. Building 7 was not hit by a plane. ‘Building 7′, ‘WTC 7′. "

HM: " The collapse time was at least 16 soconds, inside the building.

WHAT IN HELL WOULD HAVE BEEN WRONG TO EXPLODE WTC-7 FOM THE PLANNED CRITICAL COLUMN?

BC: " 4) Dick Cheney was incommand of NORAD on 9/11 while running war games. ‘Stand down order’. “Ofcourse the orders still stand, have you heard anything to the contrary?”.”Gave order to shootdown Flight 93.”, ‘NORAD Drills’. ‘NormanMineta’. “PEOC”

5) 6 out of the 10 Commissioners believe the 9/11 Commission report was, “Setup to fail” Co Chairs Hamilton and Kean. “It was a 30 year conspiracy”, “The white house has played cover up”, ‘Max Cleland resigned’, ‘John Farmer’.

6) FBI confiscated 84/85 Videos from the Pentagon.Pentagon Security CCTV (FOIA) does not show a757 and is clearly missing a frame. ‘Sheraton Hotel’, “Double tree’, ’Citgo”. ‘Moussaoui trial’. ‘Judicial Watch’. ‘Maguire declaration’. "

HM: No special interest.

BC: "7) Osama Bin Laden was NOT wanted by the FBI for the 9/11 attacks. “No hard evidence connecting Bin Laden to 9/11.” CIA created,trained and funded “Al Qaeda / Taliban” during the Mujahideen. OBL was a CIA asset named ‘Tim Osman’. OBL Reported dead in Dec 2001. "

HM: Osama was in that time already the most wanted terrorist in the world due to his embassy strikes in East Africa. He was a person who had means and true infor-mation of the buildings and New York security means to make the strike in that way.

For instance I cold have made it with that information in another way (link in the be-ginning) without explosives, and without fire. I wouldn´t have been the only possible person to do it in that way, but Osama was the only person to do it in his way, as it was done.

Osama Bn Laden had no kidney disease. It was a brain fatus of Hillary Clintons mental ill adviser.

BC: 8) 100’s of Firefighters and witness testimony to BOMBS/EXPLOSIONS ignored by the 9/11Commission Report. 9/11 Commission Report bars 503 1st responder eyewitnesses.”Explosions in the lobby and sub levels”, ‘Firefighter explosions’,’Barry Jennings’, ‘William Rodriguez’. "

HM: Those envets were not explositions.

BC: " 9) 100’s of firefighters and witness testimony to MOLTEN METAL ignored by the Commission report. “Like you’re in a foundry”, “NIST’s John Gross denies the existence of Molten Metal”, ‘Swiss Cheese’, “As of 21 days afterthe attack, the fires were still burning and molten steel was still running.” Leslie Robertson’. "

HM: The metal was aluminium.

BC: " 10) ‘5 Dancing Israeli’s’ arrested in ‘Mossad Truck Bombs’ on 9/11 that stated “We werethere to document the event.” ‘Urban Moving Systems’ front company, ’Do-minic Suter’. “$498,750 Business loan (June 2001)”. “OfficerDeCarlo’, ‘Art Students’, ‘Israeli Spying’. "

HM: No interest.

BC: " 11) On September 10th, 2001. Rumsfeld reported $2.3 TRILLION missing from the Pentagon.‘Dov Zakheim’ Pentagon Comptroller.Former VP of ‘Systems Planning Corporation’ (Flight Termination System). Signatore of PNAC document.

12) 220+ Senior Military, Intelligence Service, Law Enforcement, and Government Officials question the official story. ‘9/11 Whistle blowers’, ‘Patriots for 9/11′.’Robert Bowman’, ‘Sibel Edmonds’, ‘Albert Stubblebine’, ‘Wesley Clark’, ‘MarkDayton’, ‘Alan Sabrosky’, ‘Cyntha McKinney’, ‘Jesse Ventura’, ‘KurtSonnenfeld’. “patriotsquestion911.com” "

HM: Of course this incident was immediately used to hide misconductions in the bureaucracy!

BC: " 13) Towers were built to withstand a Boeing jet(s). “I designed it for a 707 to hit it”, Leslie Robertson, WTC structural engineer. “Could probably sustain multiple im-pacts of jetliners”, “like a pencil puncturing screen netting” Frank De Martini, decea-sed  Manager of WTC Construction & Project Management. “As far as a plane knoc-king a building over, that would not happen.” Charlie Thornton, Structural Engineer. "

HM: That happened. plane were too big. They were bild to withstand accident, not planned terror strikes with all chracteristics in worst possible positions.

BC: "14) History of American False Flag attacks. ‘USS Liberty’,‘Gulf of Tonkin’, ‘Ope- ration Northwoods’, ’OKC Bombing (Murrah Building)’, ‘1993 WTC attacks’. ‘Patrick Clawson’. Project for the New American Century (PNAC) needed “a New Pearl Harbor”, ”Rebuilding America’s Defenses”. 9/11 Achieved those goals. ‘Anthrax’. "

HM: Interesting but not evidence.

BC: " 15) BBC correspondent Jane Standley reported the collapse of WTC 7 (Solo-man Brothers building) 20 minutes before it happened. CNN/FOX/MSNBC also had early reports. ‘BBC wtc 7′,’Jane Standley’, Ashleigh Banfield’. "

HM: Interesting but not important. It would have been nothing wrong to exlode WTC-7. It woud have been also possible, on the contrary to the high towers.

B: " 16) “Flight 93″ debris was spread out over many miles. Cheney admits to giving the order to shoot down 93. “shot down the plane over Pennsylvania” Rumsfeld, “no-thing that you could distinguish that a plane had crashed there” ‘Chris Konicki. “Not a drop of blood” Coroner Wallace Miller. “there was no plane.” Mayor Ernie Stull. "

HM: Nothing to do with the towers.

BC: " 17) Bush hesitated for 441 days before starting the 911 Commission. ‘Jersey Girls’. ‘Phil Zelikow’ already wrote the outline before the commission began. ‘Steel shipped overseas’. JFK and Pearl Harbor commissions were started within 7 days. "

HM: Interesting but not important,

BC: " 18) The 911 commission was only given $15 million to investigate 9/11. Initially only $3 million was given. ‘Not enough money’. (Over $60 Million was spent investigating Clintons’ affairs with Monica). "

HM: There must be a very good legal reason to put money in researches of a case, where the technical procees happened as it ought to happen according to fire design of the buildings.

BC: " 19) Bush said he watched the first plane crash into the North tower on TV before entering the classroom. ”The TV was obviously on.” Bush was informed about the second impact while reading ‘The Pet Goat’ with the children for at least 8 more minutes while America was under “attack”.

20) The PATRIOT ACT was written before 9/11 and signed into law on October 26th, 2001. Just 45 days after 9/11

21) Marvin Bush,director of Stratesec (Securacom,‘KuAm’) was in charge of security of the WTC, United Airlines and Dulles International Airport. All three were breached on 9/11. ICTS also provided security at 9/11 airports. ‘Marvin Bush’,‘Barry McDaniel’, ‘Wirt Walker’, ‘ICTS’, ‘WTC power downs’. "

HM: Interesting, but does not mean that the CTC towers were demolished by explosives.

BC: " 22) “Who killed John O’Neil?”. Former FBI task force agent investigating Al Qaeda / Bin Laden. Transferred by Kroll Corporation to head the security just before 9/11. John O’Neil died in the Towers. ‘Jerome Hauer’ ‘Jules Kroll’.

23) Insider trading based upon foreknowledge.‘Put Options’.Never identified insiders made millions.‘United and American Airlines’ ‘Raytheon’. ‘Missing gold’. ‘Black Eagle Trust Fund’. "

HM: They were Osama´s people. Of course they made money with the strike in stock exchange.

BC: " 24) Atleast 7 of the 19 listed hijackers are alive (BBC). No video footage of 19 hijackers or passengers boarding the 4 planes. Pilots of the 4 planes never squawked the hijacking code (7500). ‘Alive hijackers’,’ACARS’, ‘Pilots for 9/11 Truth’.

WTC 7 (The SmokingGun)

Building 7 was a 47-story skyscraper and was part of the World Trade Center comp-lex. Built in 1984, it would have been the tallest high-rise in 33 states in the United States. It collapsed at 5:20 pm on September 11, 2001 in 6.5 Seconds at free fall acceleration. It was not hit by an airplane and suffered minimal damage compared to other buildings much closer to the Twin Towers. "

HM: There would have been nothing wrong to expole WTC-7 to ensure its falling on footprints.

http://www.nist.gov/el/disasterstudies/wtc/faqs_wtc7.cfm

 

BC: " 7 FACTS about Building 7

1) If fire caused Building 7 to collapse, it would be the first ever fire-induced collapse of a steel-frame high-rise.
2) Building 7’s collapse was not mentioned in the 9/11 Commission Report.
3) According to a Zogby poll in 2006, 43% of Americans did not know about Building 7.
4) It took the federal government seven years to conduct an investigation and issue a report for Building 7.
5) 2000+ architects and engineers have signed a petition calling for a new investi-gation that would include a full inquiry into the possible use of explosives for the collapse of Building 7.
6) Numerous witnesses say the possibility of demolishing Building 7 was widely discussed by emergency personnel at the scene and advocated by the building’s owner.
7) Building 7 housed several intelligence and law enforcement agencies, and the NYC Office of Emergency Management’s Emergency Operations Center (23rd floor), more commonly known as “Giuliani’s Bunker”.

Simple Facts ofTemperatures:

~1535ºC (2795ºF) – melting point of iron.
~1510ºC (2750ºF) – melting point of typical structural steel.
~825ºC (1517ºF) – maximum temperature of hydrocarbon fires burning in the atmo-spherewithout pressurization or pre-heating (premixed fuel and air – blue flame). Dif-fuse flames burn far cooler. Oxygen-starved diffuse flames are cooler yet. The fires in the Towers were diffuse and well below 800ºC.

Source:
http://www.engineeringtoolbox.com/melting-temperature-metal…

JetFuel (JET A-1): “Commercial jet fuel is essentially kerosene…”
~260-315°C(500-599°F) – open air burning temperature of JET A-1.
~980°C(1796°F) – maximum burning temperature of JET A-1.
Sources:
http://mepetroleum.com/jet_fuel.htm
http://en.wikipedia.org/wiki/Jet_fuel

“It is believed that almost all of the jet fuel that remained on the impact floors was consumed in the first few minutes of the fire.” Source: FEMA (Page 22)
http://www.fema.gov/pdf/library/fema403_ch2.pdf

Other:
~2500ºC (4532ºF) – maximum temperature of Thermite.
~660ºC (1120ºF) – melting point of Aluminum (turns silver rapidly when cooled).
~233ºC (451ºF) – Ignition temperature of paper (No chemicals added).
~1800-2500°C (3272-4532°F) – Melting point of Concrete.

“Like you’re in a foundry.”
http://www.youtube.com/watch?v=cCdRA09pztM
———————————–

THE HARD FACTS ABOUT 9/11 (VIDEO EDITION)

9/11 – The Hard Facts (Ver.1)
http://www.youtube.com/watch?v=_Pt8wfY5wps "

 

A NEW ERRONEOUS RESEARCH ON WTC-7

ONCE MORE: There would have been nothing wrong to expole WTC-7 at the crtical column 79 to ensure its falling on footprints.

http://ine.uaf.edu/wtc7

" ... 4.7 Summary and ConclusionIn summary, several findings were made from the analyses above:

1.Columns 79, 80, and 81 did not fail at the lower floors of the building. Instead, they needed to have failed at the upper floors of the building all the way to the penthouse. Yet there were no documented fires above Floor 30. Therefore, fire did not cause the collapse of Columns 79, 80, and 81 nor the collapse of the east penthouse.

2.The hypothetical failure of Columns 79, 80, and 81 — the three easternmost core columns — would not trigger a horizontal progression of core column failures.

Therefore, the hypotheses of NIST,Arup/Nordenson,and Weidlinger that the buckling of Column 79 would trigger a progressive collapse of the entire building are invalid, and the collapse of Columns 79, 80, and 81 high in the building was a separate and distinct event.

3. Even if we assume the failure of Columns 79,80,and 81 could lead to the failure of the next row of core columns,the hypotheticalfailure of Columns 76 to 81 would over-load the exterior columns around the southeast corner of the building, rather than overloading the next row of core columns to the west, which would result in the building tipping to the southeast and notina straight-down collapse.

4. The simultaneous failure of all core columns over 8 sto-ries followed 1.3 seconds later by the simultaneous failure of all exterior columns over 8 stories produces almost exactly the behavior observed in videos of the collapse.

The collapse could have started at various floors starting at Floor 16 and below and produced the same behavior. It is our conclusion that the collapse of WTC 7 was a global failure involving the near-simultaneous failureof all columns in the building and not a progressive collapse involving the sequential failure of columns throughout the building.

Despite simulating a number of hypothetical scenarios, we were unable to identify any progressive sequence of failures that could have taken place on September 11, 2001, and caused a total collapse of the building,let alone the observed straight-down collapse with approximately 2.5 se conds of free fall and minimal differential movement of the exterior. "

 

RK: The reason of the collapse was the loss structural connection of the floors to one stiffening wall, due to fall of floor elements in picture let of line from column 44 to column 26, lower the 8. etage.

NIST´s simulation on WTC-7´s collapse:

https://www.youtube.com/watch?v=fIAK6PAeyn8

IN THE NEW RESEARCH THE STIFFNESS OF CRITICAL COLUMN 79 IS CALCUATED IN ITS ORIGINAL SUPPORT CONDITION, WHICH LEADS TO ERRONEOUS RESULTS. THE STRUCTURAL SYSTEM WAS PLANNED TO COLLAPSE ON FOOTPRINTS IF IT COLLPSES.

***

https://hameemmias.vuodatus.net/lue/2020/04/a-new-quack-reseach-on-wtc-7-collapse

"

Figure 1.1 A three-dimensional depiction of the World Center complex (FEMA, 2002).

 

Risto Koivula, MSc (eng), researcher, Tampere.

https://hameemmias.vuodatus.net/lue/2018/09/palkin-vetoakestamattoman-liitoksen-siirtymaparametrit

http://www.metallirakentamisentutkimuskeskus.fi/site/_files/on%20the%20problem%20of%20bending.pdf

 

http://rmseura.tkk.fi/rmlehti/1985/nro4/RakMek_18_4_1985_4.pdf

 

https://books.google.fi/books?id=Utaxsx4pJK8C&pg=PA535&lpg=PA535&dq=Guided+Vlasov+Beams%22&source=bl&ots=EQLrQtMx6x&sig=NnJZaDq1a79A_IT0R6NcqdnFr1E&hl=fi&sa=X&ei=ccT_Ut3bGYiEyAOGu4DQBg&ved=0CEQQ6AEwAw#v=onepage&q=Guided%20Vlasov%20Beams%22&f=false

 

http://books.google.fi/books?id=a0rHcmOHdAYC&pg=PA869#v=onepage&q&f=false

https://hameemmias.vuodatus.net/lue/2015/09/wtc-tower-were-not-demolished-with-explosives

***

 

http://ine.uaf.edu/wtc7

Project Dates

May 1, 2015 - December 31, 2019

This is a study of the collapse of World Trade Center Building 7 (WTC 7) - a 47-story building that suffered a total collapse at 5:20 PM on September 11, 2001, following the horrible events of that morning. The objective of the study was threefold:

(1) Examine the structural response of WTC 7 to fire loads that may have occurred on September 11, 2001;

(2) Rule out scenarios that could not have caused the observed collapse; and

(3) Identify types of failures and their locations that may have caused the total collapse to occur as observed.

The UAF research team utilized three approaches for examining the structural res-ponse of WTC 7 to the conditions that may have occurred on September 11, 2001.

First, we simulated the local structural response to fire loading that may have occur-red below Floor 13, where most of the fires in WTC 7 are reported to have occurred.

Second, we supplemented our own simulation by examining the collapse initiation hypothesis developed by the National Institute of Standards and Technology (NIST).

Third, we simulated a number of scenarios within the overall structural system in order to determine what types of local failures and their locations may have caused the total collapse to occur as observed.

The principal conclusion of our study is that fire did not cause the collapse of WTC 7 on 9/11, contrary to the conclusions of NIST and private engineering firms that studied the collapse.

The secondary conclusion of our study is that the collapse of WTC 7 was a global failure involving the near-simultaneous failure of every column in the building.

 

 

RK: This fake "research" does not critisize this real NIST´s simulation on WTC-7´s collapse:

https://www.youtube.com/watch?v=fIAK6PAeyn8

NIST´S FINAL REPORT:

https://www.nist.gov/publications/final-report-collapse-world-trade-center-building-7-federal-building-and-fire-safety-0

 

IN THE NEW RESEARCH THE STIFFNESS OF CRITICAL COLUMN 79 IS CAL-CULATED IN ITS ORIGINAL SUPPORT CONDITION, WHICH LEADS TO ERRO-NEOUS RESULTS.THE STRUCTURAL SYSTEM WAS PLANNED TO COLLAPSE ON FOOTPRINTS IF IT COLLAPSES.

NEITHER THERE WOULD HAVE BEEN ANY "CRIME" IN EXLODIND EMPTY WTC-7 TO FALL ON FOOTPRINTS WITH ONE LARGE CHARGE AT THE CRITICAL COLUMN 79, WHEN IT HAD BURNED 7 HOURS. 

THERE WOULD HAVE BEEN NO REASON TO HIDE,IF THAT HAD HAPPENED!

 

***

 

https://files.wtc7report.org/file/public-download/A-Structural-Reevaluation-of-the-Collapse-of-World-Trade-Center-7-March2020.pdf

 

A Structural Reevaluationof the Collapse of World Trade Center 7

 

FINAL REPORT

 

Department of Civil and Environmental Engineering Col-lege of Engineering and Mines Institute of Northern Engi-neering University of Alaska Fairbanks Fairbanks, AK 99775

Prepared for: Architects &E ngineers for 9/11 Truth

INE Report 18.17 March 2020

 

 

ABSTRACT

A Structural Reevaluation of the Collapse of World Trade Center 7 By

J. Leroy Hulsey, (1941 -)  Ph.D., P.E., S.E., University of Alaska Fairbanks And

Zhili Quan,Ph.D.,Bridge Engineer South Carolina Department of Transportation And

Feng Xiao,Ph.D.,Associate Professor Nanjing University of Science and Technology Department of Civil Engineering (left the "research" group 2016)

This report presents the findings and conclusions of a four-year study of the collapse of World Trade Center Building 7 (WTC 7) - a 47-story building that suffered a total collapse at 5:20 PM on September 11, 2001, following the horrible events of that morning. The objective of the study was threefold:

(1) Examine the structural response of WTC 7 to fire loads that may have occurred on September 11, 2001;

(2) Rule out scenarios that could not have caused the observed collapse; and

(3) Identify types of failures and their locations that may have caused thetotal collapse to occur as observed.

The UAF research team utilized three approaches for examining the structural response of WTC 7 to the conditions that may have occurredon September 11, 2001.

First, we simulated the local structural response to fireloading that may have occurred below Floor 13, where most of the fires in WTC 7 are reported to have occurred.

Second, we supplemented our own simulation by examining the collapse initiation hypothesis developed bythe National Institute of Standards and Technology(NIST).

Third, we simulated several scenarios within the overall structural system in order to determine what types of local failures and their locations may have caused the total collapse to occur as observed.

The principal conclusion of our study is that fire did not cause the collapse of WTC 7 on 9/11, contrary to the conclusions of NIST and private engineering firms that studied the collapse.

The secondary conclusion of our study is that the collapse of WTC 7 was a global failure involving the near-simultaneous failureof eve-ry column in the building. All input data,results data,and simulations that were used or generated during this study are available at

http://ine.uaf.edu/wtc7.

RK: The collapse was immediately caused by loss of lateral support of the columns due to breaking of the stiffeninng system of the building by outer walls and floors by fall of floor elements (left from girder line 26 - 44) butting to one outer wall 28 - 42 under 12. etage level.

WTC7´s:  floor strucure:

http://www.nist.gov/el/disasterstudies/wtc/faqs_wtc7.cfm

Diagram 1 - Typical WTC 7 floor showing locations of columns (numbered). The buckling of Column 79 was the initiating event that led to the collapse of WTC 7. The buckling resulted from fire-induced damage to floors around column 79, failure of the girder between Columns 79 and 44, and cascading floor failures. (Credit: NIST)

The unsupported Column 79 then buckled and triggered an upward progression of floor system failures that reached the building's east penthouse. What followed in ra-pid succession was a series of structural failures. Failure first occurred all the way to the roof line—involving all three interior columns on the easternmost side of the buil-ding (79, 80, and 81). Then, progressing from east to west across WTC 7, all of the columns failed in the core of the building (58 through 78). Finally, the entire façade collapsed.

The probable collapse sequence is described in NIST NCSTAR Report 1A, Section 2.4 and NIST NCSTAR Report 1-9, Chapter 13.

 

FR: " iii EXTERNAL PEER REVIEWERS

Gregory Szuladzinski, Ph.D

Chartered Consulting Engineer Analytical Service Company

(Only "Tuther" publictions and one collection of formulas in impact mechanics Formulas for Mechanical and Structural Shock and Impact .

 

Robert Korol, Ph.D Emeritus Professor of Civil Engineering McMaster University

...

 

 ...

4.7 Summary and Conclusion

1. Columns 79, 80, and 81 did not fail at the lower floors of the building. "

RK: This is a lie. There is no way to prove, that the floor elements "could not have fallen", like NIST says. That was a crucial part of the buildings planned mechanism to fall on footprints, if it collapses.

 

FR: " Instead, they needed to have failed at the upper floors of the building all the way to the penthouse. Yet there were no documented fires above Floor 30.

Therefore, fire did not cause the collapse of Columns 79, 80, and 81 nor the collapse of the east penthouse. "

RK: The fire did not cause their buckling collapse immediately by softening their steel, but mediatedly by falling the floor elements between their girder line 26-44 and stiffening the building outer wall 28-42 and in that way breaking tha lateral support of these columns in  their girder line´s direction.

 

FR: " 2. The hypothetical failure of Columns 79, 80, and 81 - the three easternmost core columns - would not trigger a horizontal progression of core column failures. "

RK:The Collapse mechanism was not any horizontal progressing overloading failure, but a bundle buckling of columns caused by loss of stiffening mechanism of the building.

NIST has not said anything else its Final report on WTC-7 and in its simulation there.

 

FR: " Therefore,the hypotheses of NIST,Arup/Nordenson,and Weid- linger that the buckling of Column 79 would trigger a progressive collapse of the entire building are invalid, and the collapse of Co-lumns 79,80,and 81 high in the building was a separate and distinct event. "

RK: NIST has not said in its Final report that it had been any "trigger".

The trigger of the collapse mechanism was the fire and and damages from debris from the towers.

The progessive failure part of the collapse system were the falling floor elements dropping one another between girder lines girder lines 26-44 and 28-42.

The role of the buckling of the planned critical colmn 79 was, that it dropped down all remaining (in upper etages) floor elements between these lines (the fall of the wall).

(It would have been also possble to explode the building at the critical column in the cellar during the fire fighing with one effective charge; it would not have needed pre-charging, and it would have looked out the same, because it wold have porsessed same way after the critical column collapse.)

 

FR:"3.Even if we assume the failure of Columns 79,80,and 81 could lead to the failure of the next row of core columns, the hypothetical failure of Columns 76 to 81 would over-load the exterior columns around the southeast corner of the building, rather than overloading the next row of core columns to the west, which would result in the building tipping to the southeast and notina straight-down collapse. "

RK: Pläp pläp pläp...

 

FR: " 4. The simultaneous failure of all core columns over 8 stories followed 1.3 seconds later by the simultaneous failure of all exterior columns over 8 stories produces almost exactly the behavior observed in videos of the collapse. "

RK: Yes: the bundle buckling of all columns.

 

FR: "  The collapse could have started at various floors starting at Floor 16 and below and produced the same behavior. It is our conclusion that the collapse of WTC 7 was a global failure involving the near-simultaneous failureof all columns in the building and not a progressive collapse involving the sequential failure of columns throughout the building. "

RK: Yes, like also NST and I say:  the bundle buckling. NIST´s video:

https://www.youtube.com/watch?v=fIAK6PAeyn8

 

FR:"Despite simulating a number of hypothetical scenarios,we were unable to identify any progressive sequence of failures that could have taken place on September 11, 2001, and caused a total col-lapse of the building, let alone the observed straight-down collapse with approximately 2.5 se conds of free fall and minimal differential movement of the exterior. "

RK: There was no free fall in structures: in the same time parly acceleratd and partly hindered faa is not free fall. NIST speaks abot "free lall speed" - which is a jounalistic mistake of some physically ignorant issue secretary practitioneer... "

 

***

 

https://www.tms.org/pubs/journals/jom/0112/eagar/eagar-0112.html

" Feature: Special Report

Why Did the World Trade Center Collapse? Science, Engineering, and Speculation

Thomas W. Eagar and Christopher Musso

 

Editor’s Note: For a more complete. updated analysis of the World Trade Center towers collapse, read “The Role of Metallurgy in the NIST Investigation of the World Trade Center Towers Collapse” in the December 2007 issue.''

There have been numerous reports detailing the cause of the World Trade Center Tower collapse on September 11,2001. Most have provided qualitative explanations; however, simple quantitative analyses show that some common conclusions are incorrect; for example, the steel could not melt in these flames and there was more structural damage than merely softening of the steel at elevated temperatures. Some guidelines for improvements in future structures are presented.

INTRODUCTION

The collapse of the World Trade Center (WTC) towers on September 11, 2001, was as sudden as it was dramatic; the complete destruction of such massive buildings shocked nearly everyone.Immediately afterward and even today,there is widespread speculation that the buildings were structurally deficient, that the steel columns mel-ted, or that the fire suppression equipment failed to operate. In order to separate the fact from the fiction, we have attempted to quantify various details of the collapse.

The major events include the following:

Each will be discussed separately, but initially it is useful to review the overall design of the towers.

THE DESIGN

The towers were designed and built in the mid-1960s through the early 1970s. They represented a new approach to skyscrapers in that they were to be very lightweight and involved modular construction methods in order to accelerate the schedule and to reduce the costs.

To a structural engineer, a skyscraper is modeled as a large cantilever vertical column. Each tower was 64 m square, standing 411 m above street level and 21 m below grade. This produces a height-to-width ratio of 6.8. The total weight of the structure was roughly 500000 t,but wind load,rather than the gravity load, dominated the design. The building is a huge sail that must resist a 225 km/h hurricane. It was designed to resist a wind load of 2 kPa — a total of lateral load of 5,000 t.

In order to make each tower capable of withstanding this wind load, the architects selected a lightweight “perimeter tube” design consisting of 244 exterior columns of 36 cm square steel box section on 100 cm centers (see Figure 3). This permitted windows more than one-half meter wide. Inside this outer tube there was a 27 m × 40 m core, which was designed to support the weight of the tower. It also housed the elevators, the stairwells, and the mechanical risers and utilities. Web joists 80 cm tall connected the core to the perimeter at each story. Concrete slabs were poured over these joists to form the floors. In essence, the building is an egg-crate construction that is about 95 percent air, explaining why the rubble after the collapse was only a few stories high.

The egg-crate construction made a redundant structure (i.e., if one or two columns were lost, the loads would shift into adjacent columns and the building would remain standing). Prior to the World Trade Center with its lightweight perimeter tube design, most tall buildings contained huge columns on 5 m centers and contained massive amounts of masonry carrying some of the structural load. The WTC was primarily a lightweight steel structure; however, its 244 perimeter columns made it “one of the most redundant and one of the most resilient” skyscrapers. ¹

THE AIRLINE IMPACT

The early news reports noted how well the towers withstood the initial impact of the aircraft; however, when one recognizes that the buildings had more than 1,000 times the mass of the aircraft and had been designed to resist steady wind loads of 30 times the weight of the aircraft, this ability to withstand the initial impact is hardly sur-prising. Furthermore, since there was no significant wind on September 11, the outer perimeter columns were only stressed before the impact to around 1/3 of their 200 MPa design allowable.

The only individual metal component of the aircraft that is comparable in strength to the box perimeter columns of the WTC is the keel beam at the bottom of the aircraft fuselage. While the aircraft impact undoubtedly destroyed several columns in the WTC perimeter wall, the number of columns lost on the initial impact was not large and the loads were shifted to remaining columns in this highly redundant structure. Of equal or even greater significance during this initial impact was the explosion when 90000 L gallons of jet fuel, comprising nearly 1/3 of the aircraft’s weight, ignited. The ensuing fire was clearly the principal cause of the collapse (Figure 4).

THE FIRE

The fire is the most misunderstood part of the WTC collapse. Even today, the media report (and many scientists believe) that the steel melted. It is argued that the jet fuel burns very hot, especially with so much fuel present. This is not true.

Part of the problem is that people (including engineers) often confuse temperature and heat. While they are related,they are not the same. Thermodynamically, the heat contained in a material is related to the temperature through the heat capacity and the density (or mass). Temperature is defined as an intensive property, meaning that it does not vary with the quantity of material, while the heat is an extensive property, which does vary with the amount of material. One way to distinguish the two is to note that if a second log is added to the fireplace,the temperature does not double; it stays roughly the same,but the size of the fire or the length of time the fire burns,or a combination of the two,doubles.Thus,the fact that there were 90000 L of jet fuel on a few floors of the WTC does not mean that this was an unusually hot fire. The tempe-rature of the fire at the WTC was not unusual, and it was most definitely not capable of melting steel.

In combustion science, there are three basic types of flames, namely, a jet burner, a pre-mixed flame, and a diffuse flame. A jet burner generally involves mixing the fuel and the oxidant in nearly stoichiometric proportions and igniting the mixture in a con-stant-volume chamber.Since the combustion products cannot expand in the con-stant-volume chamber,they exit the chamber as a very high velocity,fully combusted, jet. This is what occurs in a jet engine, and this is the flame type that generates the most intense heat.

In a pre-mixed flame, the same nearly stoichiometric mixture is ignited as it exits a nozzle, under constant pressure conditions. It does not attain the flame velocities of a jet burner. An oxyacetylene torch or a Bunsen burner is a pre-mixed flame.

In a diffuse flame, the fuel and the oxidant are not mixed before ignition, but flow together in an uncontrolled manner and combust when the fuel/oxidant ratios reach values within the flammable range. A fireplace flame is a diffuse flame burning in air, as was the WTC fire.

Diffuse flames generate the lowest heat intensities of the three flame types.

If the fuel and the oxidant start at ambient temperature, a maximum flame tempera-ture can be defined. For carbon burning in pure oxygen,the maximum is 3,200°C; for hydrogen it is 2,750°C. Thus,for virtually any hydrocarbons,the maximum flame tem- perature, starting at ambient temperature and using pure oxygen, is approximately 3,000°C.

This maximum flame temperature is reduced by two-thirds if air is used rather than pure oxygen. The reason is that every molecule of oxygen releases the heat of for-mation of a molecule of carbon monoxide and a molecule of water. If pure oxygen is used,this heat only needs to heat two molecules (carbon monoxide and water), while with air, these two molecules must be heated plus four molecules of nitrogen. Thus, burning hydrocarbons in air produces only one-third the temperature increase as burning in pure oxygen because three times as many molecules must be heated when air is used. The maximum flame temperature increase for burning hydrocar-bons (jet fuel) in air is,thus, about 1,000°C - hardly sufficient to melt steel at 1,500°C.

But it is very difficult to reach this maximum temperature with a diffuse flame. There is nothing to ensure that the fuel and air in a diffuse flame are mixed in the best ratio. Typically, diffuse flames are fuel rich, meaning that the excess fuel molecules, which are unburned, must also be heated. It is known that most diffuse fires are fuel rich because blowing on a campfire or using a blacksmith’s bellows increases the rate of combustion by adding more oxygen. This fuel-rich diffuse flame can drop the tempe-rature by up to a factor of two again. This is why the temperatures in a residential fire are usually in the 500°C to 650°C range. ^2,3 It is known that the WTC fire was a fuel-rich, diffuse flame as evidenced by the copious black smoke. Soot is generated by incompletely burned fuel; hence, the WTC fire was fuel rich — hardly surprising with 90,000 L of jet fuel available. Factors such as flame volume and quantity of soot de-crease the radiative heat loss in the fire, moving the temperature closer to the maxi-mum of 1,000°C. However, it is highly unlikely that the steel at the WTC experienced temperatures above the 750-800°C range.All reports that the steel melted at 1500°C are using imprecise terminology at best.

Some reports suggest that the aluminum from the aircraft ignited, creating very high temperatures. While it is possible to ignite aluminum under special conditions, such conditions are not commonly attained in a hydrocarbon-based diffuse flame. In ad-dition, the flame would be white hot, like a giant sparkler. There was no evidence of such aluminum ignition, which would have been visible even through the dense soot.

It is known that structural steel begins to soften around 425°C and loses about half of its strength at 650°C.⁴ This is why steel is stress relieved in this temperature range. But even a 50% loss of strength is still insufficient,by itself,to explain the WTC collapse. It was noted above that the wind load controlled the design allowables. The WTC, on this low-wind day, was likely not stressed more than a third of the design allowable, which is roughly one-fifth of the yield strength of the steel. Even with its strength halved, the steel could still support two to three times the stresses imposed by a 650°C fire.

The additional problem was distortion of the steel in the fire. The temperature of the fire was not uniform everywhere, and the temperature on the outside of the box co-lumns was clearly lower than on the side facing the fire. The temperature along the 18 m long joists was certainly not uniform. Given the thermal expansion of steel, a 150°C temperature difference from one location to another will produce yield-level residual stresses. This produced distortions in the slender structural steel, which re-sulted in buckling failures. Thus, the failure of the steel was due to two factors: loss of strength due to the temperature of the fire, and loss of structural integrity due to distortion of the steel from the non-uniform temperatures in the fire.

THE COLLAPSE

Nearly every large building has a redundant design that allows for loss of one prima-ry structural member, such as a column. However, when multiple members fail, the shifting loads eventually overstress the adjacent members and the collapse occurs like a row of dominoes falling down.

The perimeter tube design of the WTC was highly redundant. It survived the loss of several exterior columns due to aircraft impact, but the ensuing fire led to other steel failures. Many structural engineers believe that the weak points - the limiting factors on design allowables - were the angle clips that held the floor joists between the columns on the perimeter wall and the core structure (see Figure 5). With a 700 Pa floor design allowable, each floor should have been able to support approximately 1,300 t beyond its own weight. The total weight of each tower was about 500,000 t.

As the joists on one or two of the most heavily burned floors gave way and the outer box columns began to bow outward, the floors above them also fell. The floor below (with its 1,300 t design capacity) could not support the roughly 45,000 t of ten floors (or more) above crashing down on these angle clips. This started the domino effect that caused the buildings to collapse within ten seconds, hitting bottom with an esti-mated speed of 200 km per hour. If it had been free fall,with no restraint,the collapse would have only taken eight seconds and would have impacted at 300 km/h.¹ It has been suggested that it was fortunate that the WTC did not tip over onto other buil-dings surrounding the area. There are several points that should be made.

First, the building is not solid; it is 95 percent air and, hence, can implode onto itself.

Second, there is no lateral load, even the impact of a speeding aircraft, which is sufficient to move the center of gravity one hundred feet to the side such that it is not within the base footprint of the structure.

Third,given the near free-fall collapse,there was insufficient time for portions to attain significant lateral velocity. To summarize all of these points, a 500,000 t structure has too much inertia to fall in any direction other than nearly straight down.

WAS THE WTC DEFECTIVELY DESIGNED?

The World Trade Center was not defectively designed. No designer of the WTC anti-cipated, nor should have anticipated, a 90,000 L Molotov cocktail on one of the buil-ding floors. Skyscrapers are designed to support themselves for three hours in a fire even if the sprinkler system fails to operate. This time should be long enough to eva-cuate the occupants. The WTC towers lasted for one to two hours - less than the de-sign life,but only because the fire fuel load was so large. No normal office fires would fill 4,000 square meters of floor space in the seconds in which the WTC fire deve-loped. Usually, the fire would take up to an hour to spread so uniformly across the width and breadth of the building. This was a very large and rapidly progressing fire (very high heat but not unusually high temperature). Further information about the design of the WTC can be found on the World Wide Web.^5–8

WHERE DO WE GO FROM HERE

The clean-up of the World Trade Center will take many months. After all, 1,000,000 t of rubble will require 20,000 to 30,000 truckloads to haul away the material. The asbestos fire insulation makes the task hazardous for those working nearby.

Interestingly, the approximately 300,000 t of steel is fully recyclable and represents only one day’s production of the U.S. steel industry. Separation of the stone and con-crete is a common matter for modern steel shredders. The land-filling of 700,000 t of concrete and stone rubble is more problematic. However, the volume is equivalent to six football fields, 6–9 m deep, so it is manageable.

There will undoubtedly be a number of changes in the building codes as a result of the WTC catastrophe. For example, emergency communication systems need to be upgraded to speed up the notice for evacuation and the safest paths of egress. Emergency illumination systems,separate from the normal building lighting,are alrea-dy on the drawing boards as a result of lessons learned from the WTC bombing in 1993. There will certainly be better fire protection of structural members. Protection from smoke inhalation, energy-absorbing materials, and redundant means of egress will all be considered.

A basic engineering assessment of the design of the World Trade Center dispels many of the myths about its collapse. First, the perimeter tube design of the towers protected them from failing upon impact. The outer columns were engineered to stiffen the towers in heavy wind, and they protected the inner core, which held the gravity load. Removal of some of the outer columns alone could not bring the building down. Furthermore, because of the stiffness of the perimeter design, it was impossible for the aircraft impact to topple the building.

However, the building was not able to withstand the intense heat of the jet fuel fire. While it was impossible for the fuel-rich, diffuse-flame fire to burn at a temperature high enough to melt the steel, its quick ignition and intense heat caused the steel to lose at least half its strength and to deform, causing buckling or crippling. This wea-kening and deformation caused a few floors to fall, while the weight of the stories above them crushed the floors below, initiating a domino collapse.

It would be impractical to design buildings to withstand the fuel load induced by a burning commercial airliner. Instead of saving the building, engineers and officials should focus on saving the lives of those inside by designing better safety and evacuation systems.

As scientists and engineers, we must not succumb to speculative thinking when a tragedy such as this occurs. Quantitative reasoning can help sort fact from fiction, and can help us learn from this unfortunate disaster. As Lord Kelvin said,

“I often say... that when you can measure what you are speaking about, and express it in numbers, you know something about it; but when you cannot measure it, when you cannot express it in numbers, your knowledge is of a meager and unsatisfactory kind; it may be the beginning of knowledge, but you have scarcely, in your thoughts, advanced to the stage of science, whatever the matter may be.”

We will move forward from the WTC tragedy and we will engineer better and safer buildings in the future based, in part, on the lessons learned at the WTC. The reason the WTC collapse stirs our emotions so deeply is because it was an intentional attack on innocent people. It is easier to accept natural or unintentional tragedies; it is the intentional loss of life that makes us fear that some people have lost their humanity.

References

1. Presentation on WTC Collapse, Civil Engineering Department, MIT, Cambridge, MA (October 3, 2001).
2. D. Drysdale, An Introduction to Fire Dynamics (New York: Wiley Interscience, 1985), pp. 134–140.
3. A.E. Cote, ed., Fire Protection Handbook 17th Edition (Quincy, MA: National Fire Protection Association, 1992), pp. 10–67.
4. A.E. Cote, ed., Fire Protection Handbook 17th Edition (Quincy, MA: National Fire Protection Association, 1992), pp. 6-62 to 6-70.
5. Steven Ashley, “When the Twin Towers Fell,” Scientific American Online (October 9, 2001); www.sciam.com/explorations/2001/100901wtc/
6. Zdenek P. Bazant and Yong Zhou, “Why Did the World Trade Center Collapse? — Simple Analysis,” J. Engineering Mechanics ASCE, (September 28, 2001), also www.tam.uiuc.edu/news/200109wtc/
7. Timothy Wilkinson, “World Trade Centre–New York—Some Engineering Aspects” (October 25, 2001), Univ. Sydney, Department of Civil Engineering; www.civil.usyd.edu.au/wtc.htm.
8. G. Charles Clifton, “Collapse of the World Trade Centers,” CAD Headlines, tenlinks.com (October 8, 2001); www.tenlinks.com/NEWS/special/wtc/clifton/p1.htm.

Thomas W. Eagar, the Thomas Lord Professor of Materials Engineering and Engineering Systems, and Christopher Musso, graduate research student, are at the Massachusetts Institute of Technology.

For more information, contact T.W. Eagar, MIT, 77 Massachusetts Avenue, Room 4-136, Cambridge, Massachusetts 02139-4301; (617) 253-3229; fax (617) 252-1773; e-mail [email protected].

 

***

Discussion:

fb_100001941754084 kirjoitti 17.9.2015 klo 03.29

https://www.facebook.com/groups/rebeldinos/permalink/915588105187173/

Barbara Raitzky: " Risto Koivula if you've looked at the structural steel framing of the old WTC you see tenant spaces were free of interior columns and were sold as 'open office space' by the Silverstein Company . This was considered a huge selling point but led to a lot of square footage of carpeting ... in all there was a total of 2,500,000 sq. ft. of fire-retardant carpeting combined in the Towers (and much of it didn't meet code) and as we all know - those of us who work in NYC with high-rise fire codes - there will be heavy smoke and eventually fire even with fire treatment. The same applied to the steel. It was fire-rated at something like an hour and a half and the secondary steel, which carried the decking, was rated at about an hour. The impact of the plane dislodged fireproofing of the secondary steel and penetrated into the central service/elevator core where there were numerous plumbing risers carry-ing combustible gases. So there was every possibility for intense heat despite what is being cooked up in the minds of the 911 loud-mouth conspirators. "

14. syyskuuta kello 19:06

Sacha Quatre Pattes: " Thank you, Barbara, for providing us with inside information, the sort, ironically enough, truthers would never share. "
14. syyskuuta kello 19:51

Barbara Raitzky: " Conspirators are fond of photos which show what look like small explosions at about the 70th floor but there were no 'explosions'... that was crazed, desperate people kicking out windows with debris flying. The windows in the curtain wall were only about 18" wide (a ridiculous design feature in a high-rise because nowhere was there a panoramic view of the city below as these narrow windows sat between 36" columns which blocked the view. One had to walk up to each window in between the enormous perimeter columns to view the city).... No explosions. Despe-rate people who were inhaling heavy smoke from burning carpets unable to access the stair wells and elevator shafts throwing desks and file cabinets at windows. "

14. syyskuuta kello 20:26

Risto Koivula: "The temperature of the core columns was not essential,because they did not loose their load bearing capacity due to softening of the steel, but due to the loss on lateral support from the floors, which were which stiffened the building with tube walls.

The floor trusses loose their capacity due to heat, and when such happened in two floors, the progressive collapse could start.

The core columns could not anyhow "resist" the fall of the tube "hat", because THE COLLAPSED FIRST and the tube collapsed after it. "

15. syyskuuta kello 18:33

Barbara Raitzky: " Exactly as Risto Koivula says. I'm sure he knows - that the upper floors - from about Floor 60 to the summit - the steel floor decking was purposely designed to be lighter than the lower floors allowing the Towers - as in all Manhattan high rises - to 'sway'. This 'feature' along with gravity, allowed the downward collapse within the building footprint due to the weight of the materials. Also we have heard the integrity of the joiners - bolts and fasteners - was seriously compromised after about an hour. So...with all the ASTME fire retardant testing required in New York City high rises of all fixed and movable materials the Towers collapsed in exactly the proscribed time. "

15. syyskuuta kello 16:57

 

***

fb_100001941754084 kirjoitti 17.9.2015 klo 04.54 http://www.salem-news.com/articles/may062014/russia-911-inside.php

911 Was an Inside Job ''Impossible to Conceal,'' - Vladimir Putin

Salem-News.com

First published by RT in 2011 during less tense times, this article and associated video offer keen insight into what some call, the greatest American deception...

(MOSCOW RT) - Claims that the terror attacks of September 11, 2001 were orchest-rated by US intelligence agencies are "complete nonsense," Prime Minister Vladimir Putin told attendees of a youth forum.

­"This is complete nonsense, it is impossible," Putin said on Monday, responding to a question posed by an attendee of the Seliger 2011 youth forum.

"To imagine that US intelligence services did it deliberately, with their own hands, is complete nonsense," the prime minister said. “Only people who do not understand the workings of security agencies can say that. It would be impossible to conceal it.”

Putin added that he could not imagine how "any of the current or former US leaders could have such an idea."

As the 10th anniversary of 9/11 approaches, skepticism over the official explanation of the 9/11 attacks appears to be on the rise. 9/11 “truth movements,” made up of di-verse individuals from around the world,are demanding an independent investigation into those horrific events that changed the course of history.

The International Center for 9/11 Studies, for example, is sponsoring four days of Citizen Hearings in the city of Toronto, Canada with the goal of examining “the best evidence that has been discovered in the ten years since the 9/11 events occurred.”

A group of academics – including Niels Harritt, Associate Professor at the University of Copenhagen; Steven Jones, Professor Emeritus from Brigham Young University and Kevin Ryan, former Underwriters Laboratories manager – will be among the par-ticipants who hope to persuade the public of the need for another 9/11 investigation.

There will certainly be no shortage of protesters on hand as well to condemn the “conspiracy theorists.”

The events of 9/11 were not only the worst foreign attacks ever to happen on Ameri-can soil.They also triggered a global “War on Terror,” which led to two full-scale wars among other less clearly defined military operations, and provided the impetus for a robust increase in US military spending (which has leveled off at just below $1 trillion per year).

According to the official version of events, the attacks of 9/11, organized by the now-deceased Al-Qaeda terror master, Obama bin Laden, left almost 3,000 people dead after a group of 19 terrorists hijacked four commercial jets.

The four pirated aircraft crashed into the North and South Towers of the World Trade Center complex in Manhattan, New York, the Pentagon building in Washington, and an open field just outside of Pittsburgh, Pennsylvania.

Robert Bridge, RT "

 

***

 

fb_100001941754084 kirjoitti 23.2.2019 klo 00.53

https://www.facebook.com/groups/400735243441168/1220106281504056/

Risto Koivula " Chris Sarns: Critique of WTC towers were not demolished with explosives

The author just parrots the NIST report on the collapse initiation. Evidently, he has not read any of the rebuttals.

In the graphic it says “The central core is not part of the main structural part of the building ...”

The core is most certainly part of the main structure. "

RK: Yes, I have not remarked that when changing the picture

http://www.ussartf.org/world_trade_center_disaster.htm

CS: " The author knows nothing about structure. "

RK: I am not that author. Neither is NIST or FEMA.

In my article the core in main supporting system for vertical laods.

I will correct it.

CS " He claims that if it was a controlled demolition, the Twin Towers “would have collapsed in completely different way”.

Not so. "

Yes. They would have fallen aside in exploding on a low height.

" The Twin Towers were rigged to look like a gravity collapse. "

That is impossible.

" “These towers as structural systems were originally designed to collapse into their own place”

Wrong. Buildings are designed not to collapse. "

It is right. Metal strutures are never disigned not to collapse in ANY fire conditions: they must support a needed time, which is given in legislation.


Chris Sarns: " " “the inside columns (core) bore the weight and the loads except the outer walls”

RK: This is the real condition. And opposite to the picture.

CS: " Here the author demonstrates his total lack of understanding of the laws of physics. "

The author on the picture is that WTC Memorial site (if the site is not oa falsification), not me.

I have teached also NIST and NATO and EU how the laws of physics work in structural mechanics.

https://books.google.fi/books?id=a0rHcmOHdAYC&pg=PA869#v=onepage&q&f=false

http://ristojkoivula.puheenvuoro.uusisuomi.fi/259675-riccardo-morandi-ei-ollut-ainoa-eurotieteellinen-siltaguru

http://ristojkoivula.puheenvuoro.uusisuomi.fi/261180-gradut-ja-dippikset-ja-vaikkarit-sahkoisesti-tiskiin

CS: " When floors are supported at both ends, each end carries half of the weight.

“Exterior wall tube stabilizes through the floors the effective buckling length for the core columns to the height of 4m. The effective length is inversely squared propor-tional to the load-bearing capacity, when the buckling is the dominant factor, so the double effective length causes the load-bearing capacity to fall,at worst, to 25% from the original, when bracing provided by one floor is taken away.”

That is gibberish. "

RK: It is exactly as it is.

CS: “You will have 4 tons together from the 40cm heap of steel plates on the whole element. Now, on one square meter is loaded 10 times so much load as the stan-dards allow the load, but the entire element has the load of exactly what is allowed, when it is uniformly distributed.But that way distributed it is not a bar table...The bending moment for the floor element distributes so,that the element is despite the safety factors at the limit of break. Bending moment under the "bar table" is double in comparison to that when the plates are uniformly distributed on the floor. On the other hand the own weight of the element (and trusses etc) is also about 400kg/m^2, and there are safety and overload factors, so that still it maybe possible to add load.”

RK: " More gibberish. "

It is gibberish for you due to tour ignorance.

CS: " “When it clicks into the lower element, 14 tons hard and heavy stuff falls from 4 m above on the downstairs neighbor's exactly the same kind of floor element, and guess, what happens? If there is a bar table too, it does not have influence: the more there should be falling load.”

It stands to reason that if you pile enough weight on a floor to break the supports it will fall. But in the real world that would not happen all at once. "

RK: So???!!!

CS: " A fire induce collapse would be uneven and the collapse would be chaotic. "

You are wrong already in that,that the INDUCTION, the TRIGGER, woul be essential in the collapse machanism.

But really essential is the disigned collapse system on foot-prints, for instance in a century hurricane, or a missile strike, when there are no people in the house and the elecrticity and water are turned off.

" “One such "bomb" dropped from the upper floor is sufficient drop floors in one quarter of the building and to break the structural connection between the core and one tube-wall, which means that the core columns get a degree on freedom to rotate in a bundle buckling in such a way that its carrying capacity is lost, and the core also drops in the "pipe" in the same way, as it took place in reality.”

The core would not rotate and buckle. "

RK: It would rotate. And then the bundle buckling is even for all columns, in your terms.

And that is just what it did, and that is the designed collapse system on foot-prints.

CS: " The core was not a pipe. "

RK: The TUBE was the pipe, which guided the debris on foot-prints.


CS: " It had 47 columns arranged in a grid and held together with girders like other buildings. "

RK: They were not quite like usual buildings.

The floor-truss-supporting primeary girders were very thin-walled, high and narrow C-girders.

You can see one here distorted:

https://isgp-studies.com/911-evidence-for-explosives-and-thermite-at-WTC

They do not act vertcal direction as truss or grind beams with the heavy colums.

That is a part of the planned collapsing system.

CS: “What you see "video crash" is the collapse of the empty “tube”.

The core and exterior frame work was blown outward sequentially down the building. "

RK: NO REASON OR POSSIBILITY TO LOW THEM - WITHOUT BLOWING OUT ALSO THE THE TUBE WALLlS and making the towers fall aside , not on footprints!

CS: " This article is nothing but bombastic bullshit. It’s just a vague theory with no evidence to support it. "

RK: It is true theory and needs no further evidence.

 

***

fb_100001941754084 kirjoitti 11.9.2019 klo 15.36 Юрий Антипов
18 tuntia ·

Приближается очередная годовщина 9/11. Несмотря на то, что ЧП произошло в совершенно другой стране, это событие коснулось многие страны, в том числе, и Россию.
Разговоров о причинах обрушения трёх зданий было очень много. И уже найде-но много фактов, которые не вписываются в официальное объяснение,что про- изошло естественное обрушение башен из-за возникшего пожара на этажах. Я сейчас не буду приводить все факты. Остановлюсь лишь на двух. И эти факты хорошо известны.
На фото №1 фото начало разрушения южной башни ВТЦ. Плиты перекрытия в момент разрушения и падения их вниз как поршни выталкивают воздух с этажа.

Но.....На фото мы видим, что начали рушится верхние этажи. Но гораздо ниже (не менее 10 этажей ниже -это видно по ещё неразрушенным углам здания) сильнейшее давление на этом нижнем этаже выбрасывает дым направленной струёй. См. на фото №1 правую сторону здания, ниже облаков дыма.
Так что же вызвало такой мощный выброс дыма с этажа, над которым ещё нетронутыми разрушениями находится десяток этажей??Ответ напрашивается сам собой, учитывая специфику падения башен.....
Но этот факт можно рассматривать как приложение к другому, ещё более на-глядному факту, который сходу отрицает естественное (от пожара) обрушение башен.
Силовой каркас зданий ВТЦ был собран из мощных пустотелых железных балок прямоугольного сечения. И понятно, что под весом разрушенной вверху конструкции, нижний пояс вертикальных балок (находящийся ближе к земле) должен был деформироваться, плющиться, обрываться по местам стыковок, скручиваться и т.д. См.фото №2.
Но совершенно не стыкуется с официальной версией то состояние некоторых колонн, которое было обнаружено на месте обрушения. Причём эти колонны (балки) не были подвержены ни пожару, ни последующей разделке газорезчиками, разбирающими упавшие конструкции здания.
Почему не были подвержены пожару? Потому что на фото показаны призем-ные колонны. Почему их не касалась рука газорезчика? Да потому что, при разрезании стальной конструкции газорезчик ВСЕГДА делает разрез по мини-мальному периметру, то есть перпендикулярно разрезаемому элементу. Здесь же на фото мы видим косой рез. И этот рез делался такой высокой температурой, что расплавленный металл потёк вниз.
Далее, ещё один момент. Кто работал с газорезкой, то знает, что струя горяще-го газа (ацетилен с кислородом) сдувает расплавленный метал внутрь разреза-емой конструкции. Здесь же расплавленный металл в большом количестве тёк по наружной поверхности балки.
Если балка режется, то режется она по всему периметру. Но балка на фото имеет не оплавленный металл на своих углах.
И всё, что мы видим на фото №3 и фото №4 говорит только обо одном. Что эта балка стала обрезанной не вследствие обрушения здания. А то,что здание теряло свою устойчивость именно из-за таких балок. И эти балки были искусственно обрезаны до начала обрушения здания.
И именно так взрывники с помощью термита обрушают вышедшие из эксплуа-тации здания. См фото №5.Причём укладка термита вокруг срезаемой колонны идёт именно под углом, чтобы разрезанная колонна не накренялась в бок, а, потеряв опору, сползала по наклонной вниз, тем самым, сводя площадь обрушения до минимума.
Один человек из США, считающий себя большим специалистом в области строительства, сразу после этого ЧП дал интервью в СМИ. И на камеру сказал, что по его мнению, однозначно, что башни упали не из-за пожара. Прошло время, и этот человек "владелец заводов, газет, пароходов" стал Президентом США. И что? "За кусток, под мосток и молчок...". Оказался слаб в коленках... Ну, как та колонна на фото №4. Не выдержал внешнего рукотворного воздействия. Впрочем, как и со спутниковым фото, где как на ладони видна вся причина трагедии с рейсом МН17. Слаб человек. "

 

***

I have expained these all...
 

https://www.facebook.com/legacy/notes/286150864825815/