[Moderated]Another engineer criticizes NIST & FEMA

[technoextreme]

Serious readers of this thread...

allow me to make a practical recommendation:


A solid understanding of "the story" told in the NCSTAR 1-5A/9/C WTC2 time-line is essential to fully appreciating - and meaningfully participating in - this thread.


No. A solid understanding of the field of civil engineering is essential to even understanding the paper. Im not going to delude myself into thinking that Im going to understand that paper.

[Max Photon]

No. A solid understanding of the field of civil engineering is essential to even understanding the paper.


Wrong.

NCSTAR 1-5A/9/C is simply a visual account of phenomena observed on WTC2's facade.

If you can bird(brain) watch, you can read NCSTAR 1-5A/9/C

Why, some astute spotters claim to have seen even the Gravy-Billed Sucker Plucker hunting and pecking at it.


Im not going to delude myself into thinking that Im going to understand that paper.


(or apostrophes)


Ah, the power of positive thinking.

Well at least you are honest.



Is it just me, or are there brilliant minds in these parts?


Max

---

[chillzero]

Due to the number of reports generated by this thread, it is now being moderated.

[Max Photon]

---

Apollo20 my dear chap,


Phase transformation completed.


Now, would you be gracious enough to do a quick summary of this thread thus far, and some hints as to where you'd like to go?

This reader is very interested.


With maximum respect,

Max

---

[DGM]

Apollo or Max;
I really would like to know how fire proofing of the dampers would come in to play. All the load bearing members being protected would seem to be the critical parts. Surely your not saying that the dampers could have arrested the collapse.

[technoextreme]

Wrong.

NCSTAR 1-5A/9/C is simply a visual account of phenomena observed on WTC2's facade.

If you can bird(brain) watch, you can read NCSTAR 1-5A/9/C

Why, some astute spotters claim to have seen even the Gravy-Billed Sucker Plucker hunting and pecking at it.
No it's not simply a visual account. It didn't even take me five minutes to realize this fact.
Ah, the power of positive thinking.

Well at least you are honest.
But your not.:)
(It's actually incredibly exciting. And bizarre - very bizarre.)

What's your definition of bizarre though.

Ah, the power of positive thinking.

Well at least you are honest.
Actually Im smart enough to know your making stuff up. Lord knows I would like to know what ground water had to do with 9/11.

[Furcifer]

Inretrospect the whole building should have been covered in fireproofing, top to bottom. It wasn't, therefore this was a design flaw? I'm not following the logic progression here on the dampeners. You can't just spray fireproofing willy nilly on stuff, especially equipement designed to work in a dynamic state. Seems to me like covering a safety device, thereby restricting its movement would impair it. Plus who knows what kind of chemical interaction would happen? If the foam retained moisture, would the resulting corrosion and pitting on the actuator rod lead to failure?

[Max Photon]

Apollo or Max;
I really would like to know how fire proofing of the dampers would come in to play. All the load bearing members being protected would seem to be the critical parts. Surely your not saying that the dampers could have arrested the collapse.


What-o DGM?


Here is what I see:


WTC2 Floor 81 had a UPS room.

The "UPS batteries" had iron instead of lead, and salt-water instead of acid. The "UPS batteries" were in fact rust generators.

When Flight 175 hit the tower, the front landing gear penetrated the rust generators, throwing up a screen of iron oxide and water into the oncoming shattered aluminum.

(The absorption of the jet's energy by the rust generators might account for the "catcher's mitt" effect Apollo20 commented on earlier.)

Naturally-occurring, small thermite sparks ignited a thermite reaction in the presence of water, creating a phreato-thermatic explosion (which in turn helped to drive a fuel-air explosion.)

This engineered phreato-thermatic explosion provided added energy to knock off SFRM from many different types of steel members and components.


Incidentally, the phreato-thermatic explosion also helped to create a spectacular visual input signal, that would be fed into the media, to excite resonance in such harmonics as blind hatred, racism, irrational jingoism, flag-wrapping, belligerence, and so forth. These necessary illusions were required to manufacture consent to illegally invade other sovereign nations, and install a police state here in the SubprimeHomeLand.

The phreato-thermatic explosion also created some pools of molten iron on the impact floors, which pooled at low spots, heated the trusses through the concrete, which caused the floors to sag even more, encouraging more pooling, thereby creating a dynamic floor-loading mechanism.


The rust generators created a "debris shadow" - the Cold Spot.

It was planned that debris on either side of the Cold Spot would collect at under column splices - which were engineered to become hot spots.


Thermite had been planted at perimeter connections: column splices, spandrel splices, floor truss seats, and gusset seats.

The thermite was simply poured into box columns and spandrel-splice gaps.

For the floor truss seats and gusset seats, the thermite was wrapped in paper and black plastic.

The thermite was linked and ignited by thermite-dusted shock-tube, and the shock-tube was remotely ignited by laser from WTC7.

Note that the thermite-dusted shock-tube was able to light the planted thermite directly, and that the planted thermite was able to ignite out-lines of (other) shock-tube. In other words, the planted thermite could serve as a one-to-many relay.


The thermite was designed not to cut, melt, or slice the steel, but to heat-weaken it, by heating the steel to about 600C (though some components were heated to 1100C).

If steel was heated well before collapse initiation, it cooled, and became more brittle.

If the steel was still hot at collapse initiation, the steel would have been ductile.

By controlling the variables of time and temperature, a natural-looking spectrum of failure modes was engineered.


Depending on where the thermite was planted - that is, depending on the splice or connection - different phenomena were observed on the exterior as the thermite burned.


Thermite at floor truss seats produced flames and smoke at the base of windows.


Thermite at gusset seats produced flames, and bright flashes at the "tops of windows". (NIST should have said at the "bottom of spandrels.")

Thermite at gusset seats caused the visco-elastic dampers to burn, which created black smoke to mask the white aluminum-oxide ash.


Thermite in most box columns was used in small quantities. But it was enough to blow the bolt-access-hole covers off, creating NIST's unexplained "pressure pulses"

Thermite was packed into WTC2/81/301, and was the source of the 10-minute metal fire about which NIST dribbled in its bib.

Burning thermite spewed out of this column (and others) onto debris piles, creating NIST's "fires burning on piles of debris" or similar.

By controlling where and when columns spewed out burning thermite onto piles of debris, demolition planners were able to create the illusion of intense fires migrating across the faces, hots spots and cold spots (which created differential heating, and buckling) and other phenomena.

The iron from column 301 accounts for much of the metal flows.


Thermite in spandrel splice gaps accounts from the white glows on top of spandrels, and at least one of the WTC2 metal flows.


The ignition of all of the above in timed sequences accounts for the "steam pipe organ" effects, the smoke puffs, the pressure pulses, the metal fire, the metal flows, the falling debris, the intense smoke release, the fires that violate normal fire behavior, the intense white glows, the white "smoke", the hanging objects changing location, and on and on.



The way to think of the dampers is that they were one of several exploitable susceptibilities:

- Flammable visco-elastic dampers
- A325 column splice bolts
- Thin spandrel splice plates
- Top chords at truss seats


Never ever forget - the pre-engineered narrative called for:

Loss of SFRM allowed trusses to be heated from below, which caused them to sag, which pulled perimeter columns inward, which caused the columns to bow, which caused them to fail, which initiated the collapse of WTC2.

NIST is leaving out that thermite was used to heat-weaken steel connections.

So the weakening of the visco-elastic dampers was just one step in causing the floors to sag in a manner consistent with the narrative.

Plausible deniability required it.


Remember, it is not the collapse, but collapse initiation that is of interest.

The visco-elastic dampers had a role in the engineering of the collapse initiation.


Max

---

[Furcifer]

Max: Thanks, it's so obvious now.

[Apollo20]

MAXWELL:

Max MIHOP surely means AP-spiked SFRM as well...........

[DGM]

Ok Max.

Apollo20;
Do you care to field my question?

[technoextreme]

This engineered phreato-thermatic explosion provided added energy to knock off SFRM from many different types of steel members and components.

What the hell does ground water have to do with this explosion? In all seriousness. I looked the words up in a dictionary. Answer that question.

The thermite was designed not to cut, melt, or slice the steel, but to heat-weaken it, by heating the steel to about 600C (though some components were heated to 1100C).

Actually you don't need thermite to get the weakened steal. All you need is a large amount of fuel.:)

[DGM]

What the hell does ground water have to do with this explosion? In all seriousness. I looked the words up in a dictionary. Answer that question.
He needs lots of water to produce the rust he needs........... Don't ask........

[~enigma~]

What the hell does ground water have to do with this explosion? In all seriousness. I looked the words up in a dictionary. Answer that question.
If he used the proper name maybe you can see why water is needed. He made up the term phreato-thermatic but the proper term is phreatomagmatic

[Max Photon]

What the hell does ground water have to do with this explosion? In all seriousness. I looked the words up in a dictionary. Answer that question.




Very well.

Here is an excerpt from a post of mine, the link to which can be found here:

http://forums.randi.org/showthread.php?postid=2757227#post2757227


* * *

"...the improvised thermite, which in the presence of water, created a spectacular phreato-thermatic explosion!


Phreato means ground water, or underground water.


Some object to my phrase, saying that is should be called a phreato-magmatic explosion, in which ground water meets magma (or something molten), creating a steam - or littoral - explosion.


I believe phreato-thermatic is more appropriate.

Underground can also mean clandestine.

Phreato = clandestinely-placed water.

Also, the reaction I propose creates more than just a steam explosion.

A thermite reaction is twice as hot as orange flowing magma.

A DU-penetrator is twice as hot still.
[Note: I no longer need the DU penetrator.]

At these high temperature, water is energetically driven past the steam phase, and is broken into its constituent hydrogen and oxygen.

This creates a colorless hydrogen explosion (as seen in the thermite/ice explosion videos).

So a phreato-thermatic explosion has more bang than a phreato-magmatic (steam) explosion.

Last, I use thermatic instead of thermitic because the reaction I propose includes sulfur from the building material, in particular, from the gypsum.

Phreato-thermatic explosion."

* * *


I hope that clarifies my choice of words.

Max

---

[Max Photon]

MAXWELL:

Max MIHOP surely means AP-spiked SFRM as well...........


Apollo20,

I am not sure I follow you.

MAX-MIHOP is Maxwell C. Photon's particular model.

It so happens that MAX-MIHOP is similar in many respects - minus the catalyst - to APOLLO20-MIHOP, an elegant model using ammonium-perchlorate-spiked SFRM.

Are you seeing more overlap than I do?

Is your model starting to incorporate some of MAX-MIHOP's cunning innovations, hmmmm?

If so, I'd love to hear about it.

(I'd also like to have little hidden web-cams to see others' reactions.)


There is a beautiful saying:

The information is in the errors.

I think it would be fun to try and articulate MAX-MIHOP and APOLLO20-MIHOP as succinctly as possible, and subject them to some of the anomalies described so beautifully by NIST in NCSTAR 1-5A/9/C.

May the best fit win.


I say it all the time: I can switch models in a flash; I am beholden to nothing.

If AP explains the 10-minute metal fire, the pressure pulses, the 7 intense smoke releases, etc., then MAX-MIHOP will plunder your model for the good parts. (It's like a PacMan game out there.)


If there is something better, I want to know about it.

If my models are winning, I want to know about that too.


Cheers!

Max

---

[TellyKNeasuss]

The thermite was linked and ignited by thermite-dusted shock-tube, and the shock-tube was remotely ignited by laser from WTC7.

I still don't understand why they didn't just use the laser to cut the columns. Think of all the tax money that could have been saved; money that could have been used for further tax cuts for the rich.

By controlling where and when columns spewed out burning thermite onto piles of debris, demolition planners were able to create the illusion of intense fires migrating across the faces, hots spots and cold spots (which created differential heating, and buckling) and other phenomena.

And the smoke came from? (Why am I even asking this question?)

[technoextreme]

Phreato means ground water, or underground water.
Phreato just means ground water. Nothing more than that.
At these high temperature, water is energetically driven past the steam phase, and is broken into its constituent hydrogen and oxygen.

This creates a colorless hydrogen explosion (as seen in the thermite/ice explosion videos).
No the thermite ice explosions that your seeing isn't caused by hydrogen. It's just a steam explosion.

[GregoryUrich]

Yes, Kevin Ryan has been telling this lie for some time. I cover it on Page 19 of my whitepaper.

The NIST Report says that the aggregate KE of impacting fragments need to be roughly 1 MJ (actually they say 0.1 to 1 MJ) to shake loose a square meter of SFRM. But this does not mean that the SFRM absorbs all of this energy. The vast majority of energy remains to damage the structure underneath or ricochet the impacting fragments into other SFRM somewhere else.

Kevin Ryan not only uses 1 MJ / m2, disingenuously using the top of the range, but also assumes all of that energy is absorbed. If a three-quarter inch layer of SFRM could do that, we should use it as armor on main battle tanks.

However, since this is "Bash NIST Day," I will add that I don't understand why they used energy and not momentum in the above expression. I believe that momentum is actually the correct quantity, and their use of KE leads to further confusion. Probably has no impact at all on their overall conclusions, though.

In NCSTAR1-5D, NIST suggests that 66% of the airplanes KE was transferred into the building's KE (movement of the building). This would mean that only 34% of the KE is left to actually damage the building and SFRM, unless of course the movement of the building caused damage.

I find nowhere else in NIST, including the 1-2 Airplane Impact Analysis series, that this is taken into account. In fact, they compare the NIST results to Wierzbicki's study which applied the entire energy to destroying the airplane and damaging the building and had fairly similar results.

[rwguinn]

In NCSTAR1-5D, NIST suggests that 66% of the airplanes KE was transferred into the building's KE (movement of the building). This would mean that only 34% of the KE is left to actually damage the building and SFRM, unless of course the movement of the building caused damage.

I find nowhere else in NIST, including the 1-2 Airplane Impact Analysis series, that this is taken into account. In fact, they compare the NIST results to Wierzbicki's study which applied the entire energy to destroying the airplane and damaging the building and had fairly similar results.

So, that energy just....disappears?

[Apollo20]

NIST 1-5D states:

"To assess the response of the tower at the end of the impact, it was necessary to consider the kinetic energy transferred from the airplane to the tower. .... It was assumed that two-thirds of the energy was transferred from the airplane to the structure."

This means that the aircraft itself absorbed one third of the impact energy, basically by being shredded...

[GregoryUrich]

So, that energy just....disappears?

NIST doesn't say. I would assume the KE (swaying of the building) is absorbed by the visco-elastic dampers and dissipated as heat. This would mean that the energy is no longer available to damage the building.

[technoextreme]

So, that energy just....disappears?
No. It just gets converted into some other form of energy. If the building rocks back and forth that energy gets dissipated in the form of heat.
This means that the aircraft itself absorbed one third of the impact energy, basically by being shredded...
Im assuming that the flying pieces of shrapnel includes the 2/3 of the energy that damaged the building. Right?

[rwguinn]

NIST 1-5D states:

"To assess the response of the tower at the end of the impact, it was necessary to consider the kinetic energy transferred from the airplane to the tower. .... It was assumed that two-thirds of the energy was transferred from the airplane to the structure."

This means that the aircraft itself absorbed one third of the impact energy, basically by being shredded...
Thank you fot the quote.
So, Gregory Urich... How does one get from "the kinetic energy transferred from the airplane to the tower. .... It was assumed that two-thirds of the energy was transferred from the airplane to the structure" to "NIST suggests that 66% of the airplanes KE was transferred into the building's KE (movement of the building). "
The energy ransfer was energy transfer. It takes a different comprehension to read "..energy was transferred from the airplane to the structure" as "KE energy was transferred from the airplane to KE of the structure"

[cloudshipsrule]

If there is something better, I want to know about it.

If my models are winning, I want to know about that too.

FYI, the better model is that airplanes hit the buildings, the damage and fire initiated collapse. Yours is pretty good too, though.

[GregoryUrich]

No. It just gets converted into some other form of energy. If the building rocks back and forth that energy gets dissipated in the form of heat.
Im assuming that the flying pieces of shrapnel includes the 2/3 of the energy that damaged the building. Right?

NIST 1-5D states:

"To assess the response of the tower at the end of the impact, it was necessary to consider the kinetic energy transferred from the airplane to the tower. .... It was assumed that two-thirds of the energy was transferred from the airplane to the structure."

This means that the aircraft itself absorbed one third of the impact energy, basically by being shredded...

In NCSTAR1-5D (p.43-44), NIST very clearly states that 66% of the energy goes into the KE (= 1/2 x mv^2) of the building. I.e. the building (or rather some portion of it) and the airplane are moving together at 42.3 ft/s at the end of impact. What happens to this energy after that point is not discussed.

This part of the NIST reports seems to be one of the weakest. On p. 45 they calculate the accelleration for the building based on a velocity of 42.3 ft/s after 0.63 and get 0.25g (2.46 m/s^2). The minimum accelleration to attain 42.3 ft/s in 0.63 seconds is around 67 ft/s^2 or more than 2g. If the accelleration was constant (it was higher earlier in the impact) the building would be displaced around 13 ft which should have been visible on the videos.

T. Wierzbicki et al. estimated that the energy for destroying the aircraft was 586 MJ. The total KE for the planes was 2540 MJ and 3658 MJ for WTC1 and WTC2 respectively. This gives 16-23% of KE for destroying the planes. So only 11-18% would be left for flying debris.

To summarize, I think NIST's big mistake was guessing that 66% of the planes KE was tranferred to the tower in the form of KE.

[pomeroo]

WildCan't,

I believe the point is that even though Flight 175 struck the tower wingtip to wingtip, 175 struck the tower off-center, thereby exciting torsional harmonics.

These harmonics absorbed energy.

These harmonics ought to be accounted for.

Stay tuned!

Max

---


Gee, Max, imagine if the real scientists knew the stuff you make up. NIST, for example, could have explained why one Tower remained standing longer than the other by showing that the angles at which the planes hit made a difference.

What? NIST did exactly that?

Never mind.

[pomeroo]

What-o DGM?


Here is what I see:


WTC2 Floor 81 had a UPS room.

The "UPS batteries" had iron instead of lead, and salt-water instead of acid. The "UPS batteries" were in fact rust generators.

When Flight 175 hit the tower, the front landing gear penetrated the rust generators, throwing up a screen of iron oxide and water into the oncoming shattered aluminum.

(The absorption of the jet's energy by the rust generators might account for the "catcher's mitt" effect Apollo20 commented on earlier.)

Naturally-occurring, small thermite sparks ignited a thermite reaction in the presence of water, creating a phreato-thermatic explosion (which in turn helped to drive a fuel-air explosion.)

This engineered phreato-thermatic explosion provided added energy to knock off SFRM from many different types of steel members and components.


Incidentally, the phreato-thermatic explosion also helped to create a spectacular visual input signal, that would be fed into the media, to excite resonance in such harmonics as blind hatred, racism, irrational jingoism, flag-wrapping, belligerence, and so forth. These necessary illusions were required to manufacture consent to illegally invade other sovereign nations, and install a police state here in the SubprimeHomeLand.

The phreato-thermatic explosion also created some pools of molten iron on the impact floors, which pooled at low spots, heated the trusses through the concrete, which caused the floors to sag even more, encouraging more pooling, thereby creating a dynamic floor-loading mechanism.


The rust generators created a "debris shadow" - the Cold Spot.

It was planned that debris on either side of the Cold Spot would collect at under column splices - which were engineered to become hot spots.


Thermite had been planted at perimeter connections: column splices, spandrel splices, floor truss seats, and gusset seats.

The thermite was simply poured into box columns and spandrel-splice gaps.

For the floor truss seats and gusset seats, the thermite was wrapped in paper and black plastic.

The thermite was linked and ignited by thermite-dusted shock-tube, and the shock-tube was remotely ignited by laser from WTC7.

Note that the thermite-dusted shock-tube was able to light the planted thermite directly, and that the planted thermite was able to ignite out-lines of (other) shock-tube. In other words, the planted thermite could serve as a one-to-many relay.


The thermite was designed not to cut, melt, or slice the steel, but to heat-weaken it, by heating the steel to about 600C (though some components were heated to 1100C).

If steel was heated well before collapse initiation, it cooled, and became more brittle.

If the steel was still hot at collapse initiation, the steel would have been ductile.

By controlling the variables of time and temperature, a natural-looking spectrum of failure modes was engineered.


Depending on where the thermite was planted - that is, depending on the splice or connection - different phenomena were observed on the exterior as the thermite burned.


Thermite at floor truss seats produced flames and smoke at the base of windows.


Thermite at gusset seats produced flames, and bright flashes at the "tops of windows". (NIST should have said at the "bottom of spandrels.")

Thermite at gusset seats caused the visco-elastic dampers to burn, which created black smoke to mask the white aluminum-oxide ash.


Thermite in most box columns was used in small quantities. But it was enough to blow the bolt-access-hole covers off, creating NIST's unexplained "pressure pulses"

Thermite was packed into WTC2/81/301, and was the source of the 10-minute metal fire about which NIST dribbled in its bib.

Burning thermite spewed out of this column (and others) onto debris piles, creating NIST's "fires burning on piles of debris" or similar.

By controlling where and when columns spewed out burning thermite onto piles of debris, demolition planners were able to create the illusion of intense fires migrating across the faces, hots spots and cold spots (which created differential heating, and buckling) and other phenomena.

The iron from column 301 accounts for much of the metal flows.


Thermite in spandrel splice gaps accounts from the white glows on top of spandrels, and at least one of the WTC2 metal flows.


The ignition of all of the above in timed sequences accounts for the "steam pipe organ" effects, the smoke puffs, the pressure pulses, the metal fire, the metal flows, the falling debris, the intense smoke release, the fires that violate normal fire behavior, the intense white glows, the white "smoke", the hanging objects changing location, and on and on.



The way to think of the dampers is that they were one of several exploitable susceptibilities:

- Flammable visco-elastic dampers
- A325 column splice bolts
- Thin spandrel splice plates
- Top chords at truss seats


Never ever forget - the pre-engineered narrative called for:

Loss of SFRM allowed trusses to be heated from below, which caused them to sag, which pulled perimeter columns inward, which caused the columns to bow, which caused them to fail, which initiated the collapse of WTC2.

NIST is leaving out that thermite was used to heat-weaken steel connections.

So the weakening of the visco-elastic dampers was just one step in causing the floors to sag in a manner consistent with the narrative.

Plausible deniability required it.


Remember, it is not the collapse, but collapse initiation that is of interest.

The visco-elastic dampers had a role in the engineering of the collapse initiation.


Max

---


Max, you neglected to mention that no thermite was used at the WTC complex.

[cmcaulif]

The minimum accelleration to attain 42.3 ft/s in 0.63 seconds is around 67 ft/s^2 or more than 2g. If the accelleration was constant (it was higher earlier in the impact) the building would be displaced around 13 ft which should have been visible on the videos.


This is not quite accurate, the building will not be displaced 13 ft, nor anywhere near it. In this study:

Structural Responses of World Trade Center under Aircraft Attacks. Omika, Yukihiro.; Fukuzawa, Eiji.; Koshika, Norihide. Journal of Structural Engineering v. 131 no1 (January 2005) p. 6-15

The accelerations and displacements are calculated for the building, and they find that WTC 1 and 2 experienced maximum accelerations of 2g and 3g respectively, which corresponded to displacements of approx 30cm(.98ft) on the impact floor and 50cm(1.64ft) at the top floor.

[Dave Rogers]

To summarize, I think NIST's big mistake was guessing that 66% of the planes KE was tranferred to the tower in the form of KE.

It seems fairly clear to me from reading NCSTAR 1-5D that the group working in ceiling tile damage needed a value for the transfer of kinetic energy in advance of the group working on modelling the aircraft impact, so they took 66% as a best guess at that stage. That value is only used in assessing ceiling tile damage. If I had been doing the analysis I would have tried to parameterise the result and normalise it to whatever more correct value arose from the impact modelling, but that seems not to have been done. I didn't go into the report in enough detail to see how sensitive the results were to the KE transfer.

One question I would ask is what vibrational modes of the structure were excited by the impulse delivered by the airplane impact. Some of the higher order modes may have coupled into the floor trusses enough to cause significant SFRM loss, especially coupled with debris damage; I wouldn't know whether this is feasible because it isn't my specialism.

Dave

[Hokulele]

In NCSTAR1-5D, NIST suggests that 66% of the airplanes KE was transferred into the building's KE (movement of the building). This would mean that only 34% of the KE is left to actually damage the building and SFRM, unless of course the movement of the building caused damage.

I find nowhere else in NIST, including the 1-2 Airplane Impact Analysis series, that this is taken into account. In fact, they compare the NIST results to Wierzbicki's study which applied the entire energy to destroying the airplane and damaging the building and had fairly similar results.


I think that one thing you may be missing here, is that this calculation was used to determine the acceleration to be used on the shaking tables that were used to simulate what happened to ceiling tiles on floors above and below the impact area. (The formal title of NIST NCSTAR 1-5D is "Reaction of Ceiling Tile Systems to Shocks".) The report clearly states that this was not meant to be a comprehensive analysis, but an approximation to be used for a specific reason (determing the wave-form and other parameters for the shaking table).

Why are you trying to apply this set of calculations to the SFRM simulations?

[GregoryUrich]

Thank you fot the quote.
So, Gregory Urich... How does one get from "the kinetic energy transferred from the airplane to the tower. .... It was assumed that two-thirds of the energy was transferred from the airplane to the structure" to "NIST suggests that 66% of the airplanes KE was transferred into the building's KE (movement of the building). "
The energy ransfer was energy transfer. It takes a different comprehension to read "..energy was transferred from the airplane to the structure" as "KE energy was transferred from the airplane to KE of the structure"

You may, in fact, find yourself with an entirely different comprehension if you actually read p. 43-45 of NCSTAR1-5D.

[Apollo20]

The important thing to note in NIST's treatment of the aircraft impacts, as described in NCSTAR 1-5D, is the notion of a "participating mass".

Thus NIST state that about 0.6 seconds into the impact "the tower and the airplane debris were moving together at the same velocity ... 42.3 ft/s (12.9 m/s)."

(This statement turns out to be quite misleading as we shall see.)

On page 44 of NCSTAR 1-5D NIST state that the "participating mass" was 31 x 10^6 kg or only about 10 % of the mass of a tower!

Now let's check these numbers remembering that the mass of the aircraft was 124,000 kg and its velocity was 250 m/s:

K.E. after impact =1/2 Mv^2 = 1/2 x 31 x 10^6 x (12.9)^2 = 2.6 x 10^9 J

K.E. before impact = 1/2 x 124 x 10^3 x (250)^2 = 3.9 x 10^9 J

2.6/3.9 = 2/3

Q.E.D.

[PhantomWolf]

Um....., GregoryUrich how do you think that energy was transfered to the building?

[Furcifer]

Or NIST is saying 1/3 of the KE exited the building as flying debris. The rest went into destroying the building. As far as the visco-elastic dampers go, I don't know of any that are designed to operate at such high KE's over such short impulse durations. Anyone know?

[GregoryUrich]

This is not quite accurate, the building will not be displaced 13 ft, nor anywhere near it. In this study:

Structural Responses of World Trade Center under Aircraft Attacks. Omika, Yukihiro.; Fukuzawa, Eiji.; Koshika, Norihide. Journal of Structural Engineering v. 131 no1 (January 2005) p. 6-15

The accelerations and displacements are calculated for the building, and they find that WTC 1 and 2 experienced maximum accelerations of 2g and 3g respectively, which corresponded to displacements of approx 30cm(.98ft) on the impact floor and 50cm(1.64ft) at the top floor.

If the building was accellerated to 42 ft/s after 0.63 seconds as NIST describes, with constant accelleration the displacement will be around 13 ft. Actually, taking into account that the accelleration is highest earlier in the impact the displacement would be even greater. You can do the math if you don't believe me. Keep in mind this is only true in NIST's world.

I agree that, in reality, the building was not displaced 13 ft. This is just one example of the NIST investigation not conforming to reality.

[GregoryUrich]

Or NIST is saying 1/3 of the KE exited the building as flying debris. The rest went into destroying the building. As far as the visco-elastic dampers go, I don't know of any that are designed to operate at such high KE's over such short impulse durations. Anyone know?

Interpretation of NIST and contribution to the discussion is often enhanced by reading the source being discussed.

[GregoryUrich]

I think that one thing you may be missing here, is that this calculation was used to determine the acceleration to be used on the shaking tables that were used to simulate what happened to ceiling tiles on floors above and below the impact area. (The formal title of NIST NCSTAR 1-5D is "Reaction of Ceiling Tile Systems to Shocks".) The report clearly states that this was not meant to be a comprehensive analysis, but an approximation to be used for a specific reason (determing the wave-form and other parameters for the shaking table).

Why are you trying to apply this set of calculations to the SFRM simulations?

Have I said anything about SFRM in this discussion?

[GregoryUrich]

Um....., GregoryUrich how do you think that energy was transfered to the building?

In general, energy was transferred to the building in the manner described by NIST. It is the amount of energy (66% of the planes KE) that went into the KE of the "participating mass" of the building that is in error. The "participating mass" pointed out by Apollo may also be incorrect.

[Furcifer]

Oh so it's my p-poor interpretation. I get it.

[GregoryUrich]

Oh so it's my p-poor interpretation. I get it.

Have you read p. 43-45 of NCSTAR1-5D?

[Spins]

The important thing to note in NIST's treatment of the aircraft impacts, as described in NCSTAR 1-5D, is the notion of a "participating mass".

Thus NIST state that about 0.6 seconds into the impact "the tower and the airplane debris were moving together at the same velocity ... 42.3 ft/s (12.9 m/s)."

(This statement turns out to be quite misleading as we shall see.)

On page 44 of NCSTAR 1-5D NIST state that the "participating mass" was 31 x 10^6 kg or only about 10 % of the mass of a tower!

Now let's check these numbers remembering that the mass of the aircraft was 124,000 kg and its velocity was 250 m/s:

K.E. after impact =1/2 Mv^2 = 1/2 x 31 x 10^6 x (12.9)^2 = 2.6 x 10^9 J

K.E. before impact = 1/2 x 124 x 10^3 x (250)^2 = 3.9 x 10^9 J

2.6/3.9 = 2/3

Q.E.D.
I agree, also you are airing on the side of caution and using an impact velocity right at the top of the estimated range. The impact velocity is estimated at 545mph +/- 18mph, so the impact velocity could have easily been only 236 m/s:

K.E. before impact = 1/2 x 124 x 10^3 x (236)^2 = 3.45 x 10^9 J

2.6/3.45 = 3/4

I've no doubt a considerable amount of the impact energy was transferred into the structure as movement and absorbed, for example Stanley Praimnath mentioned the building swaying back and forth several times, but that value of 12.9 m/s (based on Greenings calculations) is just wrong, it has to be or there would be virtually no energy left to cause the damage we all witnessed.

Doesn't mean 9/11 was an inside job, just means that values they used to calculate the amount of ceiling tile loss for floors not directly damaged by the airplane from building motion alone are possibly incorrect.

The ceiling tiles at and around the impact zone would have been obliterated by the plane impact.

[R.Mackey]

In general, energy was transferred to the building in the manner described by NIST. It is the amount of energy (66% of the planes KE) that went into the KE of the "participating mass" of the building that is in error. The "participating mass" pointed out by Apollo may also be incorrect.

It seems to me that one reasonable way to estimate the energy transfer would be to consider the momentum -- if we model the aircraft impact as fully inelastic, we should be able to work out the peak velocity seen after the impact, and then backsolve against their simple estimated acceleration curve to estimate the peak acceleration. This in turn could give us a more defensible energy estimate. It will be hampered by pass-through of debris and absorption of momentum by the lower structure, but it should be good to +/- 25% or so.

I understood the extremely rough 66% estimate in NCSTAR1-5D as being a worst-case estimate limited to the ceiling tile dislodgement problem, not relevant to the Tower evolution as a whole. After all, 1-5D essentially concludes that tile dislodgement was expected to be minor, so it makes sense to run an excessively aggressive bounding case.

As such, I agree this is a bit sloppy, but unlikely to have any effect on the overall conclusions of the Report. I still consider the Report as a whole a B+ effort.

[cmcaulif]

If the building was accellerated to 42 ft/s after 0.63 seconds as NIST describes, with constant accelleration the displacement will be around 13 ft. Actually, taking into account that the accelleration is highest earlier in the impact the displacement would be even greater. You can do the math if you don't believe me. Keep in mind this is only true in NIST's world.

I agree that, in reality, the building was not displaced 13 ft. This is just one example of the NIST investigation not conforming to reality.

The entire building will not experience this maximum acceleration, but rather only the impact floors will experience it, since it is a concentrated impulse load on one portion of the structure. The farther away you get from the impact, the acceleration will drop quite substantially. Also, the floors that do experience high accelerations will have their displacements minimized, since the horizontal movement will be resisted by the action of the framed tube perimeter. This is illustrated quite well in Omika et all(who also take into account 3% damping) where it was shown that displacements will occur all the way down to the bottom of the building due to the impact.

[rwguinn]

The entire building will not experience this maximum acceleration, but rather only the impact floors will experience it, since it is a concentrated impulse load on one portion of the structure. The farther away you get from the impact, the acceleration will drop quite substantially. Also, the floors that do experience high accelerations will have their displacements minimized, since the horizontal movement will be resisted by the action of the framed tube perimeter. This is illustrated quite well in Omika et all(who also take into account 3% damping) where it was shown that displacements will occur all the way down to the bottom of the building due to the impact.

OHHHH-Kay.
I am wondering just where this "2.5%" and 3%" damping is coming from?
% damping is expressed as the fraction 0f critical damping: z/zcrit. This value is usually less than 1.0 which is 100 %. Values greater than 1 (100%) means the system is over-damped and it will not complete a full oscillation cycle, instead, deflection will decay from maximum back to zero. 100% (1.0) means the system goes through 1 oscillation from excitation to rest, with amplitude decaying all through the cycle.
0% damping means that the system oscillates forever, at the same amplitude.
I cannot see the designers allowing the towers to oscillate for a very long time 5-10 minutes) at 1/11 Hz, with the subsequent high deflection and slow decay.
I will believe that a "Q" of 3,or a "Q" of 2.5 is real. I will not believe a "Zeta" of .02-.03 until someone provides me with a link showing how the value is derived.

Damping is a function of friction and velocity. The higher the velocity, the higher the damping value. at the single chunk of homogenous material level, this is a function of molecular friction.
Steel, for most shapes and fabrications, 2% of critical can be safely assumed. USAF and NASA allow up to 5% on most aluminum/titanium structures, without having to justify it.
Rubber, depending on composition, can provide 20->100% damping, depending on utilization. The tires on your car are about 15-20% damping, not considering the shock absorbers, which can push the overall suspension system up to around 30-50%

[Hokulele]

Have I said anything about SFRM in this discussion?


This is the post/response I was commenting on.


Yes, Kevin Ryan has been telling this lie for some time. I cover it on Page 19 of my whitepaper.

The NIST Report says that the aggregate KE of impacting fragments need to be roughly 1 MJ (actually they say 0.1 to 1 MJ) to shake loose a square meter of SFRM. But this does not mean that the SFRM absorbs all of this energy. The vast majority of energy remains to damage the structure underneath or ricochet the impacting fragments into other SFRM somewhere else.

Kevin Ryan not only uses 1 MJ / m2, disingenuously using the top of the range, but also assumes all of that energy is absorbed. If a three-quarter inch layer of SFRM could do that, we should use it as armor on main battle tanks.

However, since this is "Bash NIST Day," I will add that I don't understand why they used energy and not momentum in the above expression. I believe that momentum is actually the correct quantity, and their use of KE leads to further confusion. Probably has no impact at all on their overall conclusions, though.

In NCSTAR1-5D, NIST suggests that 66% of the airplanes KE was transferred into the building's KE (movement of the building). This would mean that only 34% of the KE is left to actually damage the building and SFRM, unless of course the movement of the building caused damage.

I find nowhere else in NIST, including the 1-2 Airplane Impact Analysis series, that this is taken into account. In fact, they compare the NIST results to Wierzbicki's study which applied the entire energy to destroying the airplane and damaging the building and had fairly similar results.


To me, it looks like you are discussing the dislodging of the SFRM rather than the ceiling tiles, but applying the ceiling tile calculation. If I misread, I apologize.

[Apollo20]

If you consider an impacted tower to be a vertical cantilever undergoing simple harmonic oscillations, the velocity at the mid point is 2pi y / T, where y is the amplitude and T is the vibrational period.

For the Twin Towers T was about 11.5 seconds, and for the aircraft impact on WTC 2, y was 0.76 meters.

It follows that the maximum velocity of a tower after impact was only about 0.4 m/s.

[Dave Rogers]

If you consider an impacted tower to be a vertical cantilever undergoing simple harmonic oscillations, the velocity at the mid point is 2pi y / T, where y is the amplitude and T is the vibrational period.

For the Twin Towers T was about 11.5 seconds, and for the aircraft impact on WTC 2, y was 0.76 meters.

It follows that the maximum velocity of a tower after impact was only about 0.4 m/s.

Doesn't that assume that only the fundamental vibrational mode is excited? I'd have thought there would be many modes available, and since the two planes impacted at different heights the vibrational spectrum excited by each would be very different. How much of the energy of the impact would have gone into higher modes - does anyone have a feel for this?

Dave

[rwguinn]

Doesn't that assume that only the fundamental vibrational mode is excited? I'd have thought there would be many modes available, and since the two planes impacted at different heights the vibrational spectrum excited by each would be very different. How much of the energy of the impact would have gone into higher modes - does anyone have a feel for this?

Dave
I have not run a modal analysis of the towers, not having a model.
However, for similar Types of structure, i.e., slender columnar structures, over 90% of the kinetic energy is in the fundamental mode.
It is pretty difficult to get any energy into excitation of secondary modes.
In the case of the towers, a SWAG on my part would put 85-90% of the energy into exciting te fundamental, and maybe 5% into the torsional mode. But I would have to have enough data to model the thing to be sure.

[cmcaulif]

OHHHH-Kay.
I am wondering just where this "2.5%" and 3%" damping is coming from?
% damping is expressed as the fraction 0f critical damping: z/zcrit. This value is usually less than 1.0 which is 100 %. Values greater than 1 (100%) means the system is over-damped and it will not complete a full oscillation cycle, instead, deflection will decay from maximum back to zero. 100% (1.0) means the system goes through 1 oscillation from excitation to rest, with amplitude decaying all through the cycle.
0% damping means that the system oscillates forever, at the same amplitude.
I cannot see the designers allowing the towers to oscillate for a very long time 5-10 minutes) at 1/11 Hz, with the subsequent high deflection and slow decay.
I will believe that a "Q" of 3,or a "Q" of 2.5 is real. I will not believe a "Zeta" of .02-.03 until someone provides me with a link showing how the value is derived.

Damping is a function of friction and velocity. The higher the velocity, the higher the damping value. at the single chunk of homogenous material level, this is a function of molecular friction.
Steel, for most shapes and fabrications, 2% of critical can be safely assumed. USAF and NASA allow up to 5% on most aluminum/titanium structures, without having to justify it.
Rubber, depending on composition, can provide 20->100% damping, depending on utilization. The tires on your car are about 15-20% damping, not considering the shock absorbers, which can push the overall suspension system up to around 30-50%

The authors cite the same paper by Mahmoodi et all that Apollo made note of a few posts back:

A Rayleigh damping of 3% was assumed for the
fundamental and secondary vibration modes, based on measurements
taken at high wind speeds (Mahmoodi et al. 1987).

[Apollo20]

I am sorry I do not have a link, but I do have TWO references, (in addition to the already quoted Mahmoodi paper), that discuss the effectiveness of the viscoelastic dampers in the Twin Towers:

1. B. Samali et al. "Use of Viscoelastic Dampers in Reducing Wind and Earthquake Induced Motion of Building Structures" Engineering Structures 17(9), 639, (1995).

On page 650 we read: "The performance of the (WTC) dampers was tested during Hurricane Gloria ... for which the total damping of the building was calculated and found to be in the range 2.5 - 3.0 % of critical damping."

2. P. R. Montpellier. "The Maximum Likelihood Method of Estimating Dynamic Properties of Structures" Masters Thesis at the University of Western Ontario (1996). Table 6.2 on page 103 provides data on measurements of wind conditions, vibrational frequencies and damping (as a % of critical) based on measurements made at the WTC between 1980 and 1993. The % damping data are in the range 1.5 % - 3.4 % with an average value ~ 2.5 %.

As for the modes of vibration of the Twin Towers, while the first translational mode of WTC 2 was excited by the aircraft impact, the second translational and the torsional modes were also significantly excited. The 1st translational mode had a vibrational period of ~ 11.5 seconds; the 2nd translational mode's period was ~ 4 seconds and the first torsional mode was ~ 5 seconds. The 2nd translational mode of vibration was excited because the aircraft hit WTC 2 well below the top of the tower. As for the torsional mode, this was excited because the aircraft hit WTC 2 off center.

[PhantomWolf]

Perhaps it is just me, but surely any energy that went into moving the towers did so AFTER the energy form the impact damaging the towers was expended. The initial overload of energy would do the damage, then once the wreakage had lost enough energy to actually damage the structure the impacts would transfer the kenitic enery from one to the other, rather than it breaking the structure. That would mean that the structure took the full impact energy load of the plane, then after the ~33% was removed by things breaking, the rest was transfered into the building as motion.

[Furcifer]

Greg: Sorry, a lame attempt at being cryptic and sarcastic at the same time. There seems to be an issue with interpreting "absorbed" and "transferred" as well as what was used as a working number as opposed to a calculation.

[rwguinn]

Perhaps it is just me, but surely any energy that went into moving the towers did so AFTER the energy form the impact damaging the towers was expended. The initial overload of energy would do the damage, then once the wreakage had lost enough energy to actually damage the structure the impacts would transfer the kenitic enery from one to the other, rather than it breaking the structure. That would mean that the structure took the full impact energy load of the plane, then after the ~33% was removed by things breaking, the rest was transfered into the building as motion.
Actually, that's not a bad layman's attempt at an axplanation.
What happens is that the structure, through its frequency response characteristics, can only absorb energy at a certain rate.
If the exciting impulse occurs at a faster rate than the structure can absorb through deflection, the excess goes into breaking and bending stuff, or back into the excitation source.
You an easily demonstrate this by finding yourself a wooden Yardstick (or, find a Meter stick if you want to be that way). Holding it by one end and shaking it, you can excite the first mode at a particular shaking frequency. Shake it faster, and the end will actually quit moving as much, and your effort will seem greater, and you will get tired quicker.
Basically, when the aircraft hit the towers, the towers couldn't get out of the way" quickly enough. The excess energy ended up shredding the aircraft and the local area of the towers where the impact took place

[Apollo20]

RWGUINN:

But strong vibrations of WTC 2 were indeed excited by the aircraft impact!

In NCSTAR 1-5D NIST use a questionable theoretical approach to show that the peak acceleration of the building was as high as 0.25 g, but remarkably, NIST do not allow for this energy sink in it's structural damage model as described in NCSTAR 1-2. Given the time and money NIST was given to investigate the collapse of the twin towers I don't know why it did not perform a proper vibrational frequency analysis of the towers - even a simplified calculation such as has been published by K. Zalka would have been useful, (See Engineering Structures 23, 1544, 2001). This would at least have provided an effective flexural rigidity (EI) for the towers from which the fundamental vibrational frequency could have been determined.

I would say that the observed deflections of WTC 2 are not consistent with the aircraft impact KE. This is made worse by the fact that NIST, (and Wierzbicki!), assume that ALL the impact KE was used for plastic deformation and fracture of the aircraft and building structures in the impact zone, leaving nothing to excite elastic vibrations of the entire building. Could the fuel-air explosion induced by the aircraft impact on WTC 2 have given the building an extra kick?

[rwguinn]

RWGUINN:

But strong vibrations of WTC 2 were indeed excited by the aircraft impact!

In NCSTAR 1-5D NIST use a questionable theoretical approach to show that the peak acceleration of the building was as high as 0.25 g, but remarkably, NIST do not allow for this energy sink in it's structural damage model as described in NCSTAR 1-2. Given the time and money NIST was given to investigate the collapse of the twin towers I don't know why it did not perform a proper vibrational frequency analysis of the towers - even a simplified calculation such as has been published by K. Zalka would have been useful, (See Engineering Structures 23, 1544, 2001). This would at least have provided an effective flexural rigidity (EI) for the towers from which the fundamental vibrational frequency could have been determined.

I would say that the observed deflections of WTC 2 are not consistent with the aircraft impact KE. This is made worse by the fact that NIST, (and Wierzbicki!), assume that ALL the impact KE was used for plastic deformation and fracture of the aircraft and building structures in the impact zone, leaving nothing to excite elastic vibrations of the entire building. Could the fuel-air explosion induced by the aircraft impact on WTC 2 have given the building an extra kick?

Again, getting high-velocity into a dynamic load case is not something that happens.
If the energies input are below those required to actually cause mechanical failure (material yield) then you would be correct. A suspended yard (or meter) stich will go though all kinds of dances and jigs if you support the ends and drop, say, a rubber eraser on it.
Suspend it by the ends and drop a brick on it, and it breaks. It never had time to respond.
By a similar phenomenon, a 1/2 inch lead ball, hitting a 2 foot square steel plate (that is simply stood upright on one edge) at 800 feet per second will knock it over. At 3000 feet per second, a lead ball 1/3 inch in diameter will go right through the same steel plate, leaving it upright

It is somewhat akin to pouring 5 gallons of liquid from a wide-mouth bottle into a 3 gallon narrow-mouth bottle. The likelihood of actually getting even 3 gallons into the narrow-mouth bottle are slim unless you do it very slowly. If you simply invert the big one over the little one, you pretty much end up with 2 empties.
Mechanical energy is the same way.

This is not totally complete, but I have not the time to go into response to a step function.
Shock and Vibration Handbook, Section 23 is pretty good--An example is Figure 23-15, equation 23.31

[Furcifer]

Or...this one time I had to take a strut assembly off my car. I got the spring off, but the shock absorber itself wouldn't come off. Not having oxy, I took a hammer to it. Despite being a "shock absorber" it was mangled by the time I broke it away and got the nut off the top. I guess it only operated under the conditions it was designed for, and not as I had abused it. It operated at a certain angle to dampen certain oscillations. Out of it's range, it was useless. After a hard blow from my hammer it could only absorb the transient effects of the wave induced..

[GregoryUrich]

This is the post/response I was commenting on.

To me, it looks like you are discussing the dislodging of the SFRM rather than the ceiling tiles, but applying the ceiling tile calculation. If I misread, I apologize.

My bad. Sometimes I forget what I have written a few days ago. I didn't intend to apply the assumptions from NCSTAR1-5D to the impact analysis (SFRM), but rather indicate that the assumptions seemed purposterous.

[GregoryUrich]

RWGUINN:

But strong vibrations of WTC 2 were indeed excited by the aircraft impact!

In NCSTAR 1-5D NIST use a questionable theoretical approach to show that the peak acceleration of the building was as high as 0.25 g, but remarkably, NIST do not allow for this energy sink in it's structural damage model as described in NCSTAR 1-2. Given the time and money NIST was given to investigate the collapse of the twin towers I don't know why it did not perform a proper vibrational frequency analysis of the towers - even a simplified calculation such as has been published by K. Zalka would have been useful, (See Engineering Structures 23, 1544, 2001). This would at least have provided an effective flexural rigidity (EI) for the towers from which the fundamental vibrational frequency could have been determined.

I would say that the observed deflections of WTC 2 are not consistent with the aircraft impact KE. This is made worse by the fact that NIST, (and Wierzbicki!), assume that ALL the impact KE was used for plastic deformation and fracture of the aircraft and building structures in the impact zone, leaving nothing to excite elastic vibrations of the entire building. Could the fuel-air explosion induced by the aircraft impact on WTC 2 have given the building an extra kick?

I think they even got the 0.25g value wrong. In think it should be 2.5g.

[Apollo20]

GregoryUrich:

Well you have a point.

In the paper by Y. Omika et al. in the January 2005 issue of the ASCE Journal of Structural Engineering there is a graph showing a calculated acceleration of ~ 3g and a displacement of 30 cm for the 80th floor of WTC 2.

NIST has some 'splaining to do!

[Max Photon]

* * *

What's an order of magnitude among friends?


* * *

[Furcifer]

an order of magnitude is exactly what it sounds like. giving it up is very hardcore.

[metamars]

Perhaps you could submit your concerns to the Union of Concerned Scientists, or, better yet, to an analogous organization of engineers? I kind of doubt that there is one, though. OTOH, UCS must have engineers, as they are concerned about the safety of nuclear reactors.

Considering the recent bridge collapse in Minneapolis, it looks like we need a Union of Concerned Engineers. Governments at various levels are not doing their jobs ito maintaining infrastructure, as became common knowledge after the Minneapolis catastrophe.

While I certainly don't agree with many things you have said re 911 collapses, I believe that you're sincere. Is your sincerity likely to be honored at JREF? Indeed, are you honoring your own life, when there are probably many scientists and engineers who, like yourself, are more interested in using their talents for public service? (As opposed to nit-picking and superficial 'apologetics', e.g.)

Perhaps you should start an NGO which focuses on engineering safety issues. Then you could get $$ from foundations, which you are going to need to do many of the kinds of work you can't do, otherwise.

I wonder where UCS gets funds from. I really don't know much about them - mostly I know of them from interviews of their members on Michio Kaku's 'Explorations in Understanding'.

I got a PM from a poster regarding American Society of Safety Engineers (ASSE) as a "starting place".

Also, the USC has a pie chart of their funding sources in their annual report.

http://www.ucsusa.org/assets/documents/ucs/annual_report_06.pdf

Membership & Contribution 56%
Foundations 28%
Planned Gifts 10%
Operations & Net Investments 7%