Another Question for Heiwa : Amazing Fireproof Steel

[Heiwa]

You would be much more correct stating that A, B and C are of equal mass/density using interconnected parts as an assembly and not solid blocks.

By the way, nice to see that you realized that gravity is a constant.

Who suggest that A, B and C are blocks?

The constant of gravity G is about 0.06673 m3/kg s² but is difficult to establish. Nobody knows its exact value. It seems some people mixed it up with gravity force F (= m a) and gravity acceleration g on the surface of the Earth (the latter not being constant as shown above).

 

[Heiwa]

And what, exactly, is trying to drop a spaghetti onto another spaghetti supposed to prove?

You missed that? Well if something is going to collapse, e.g. a slender, vertical column A in a building, when something else is dropping on it from above, e.g. another slender, vertical column B, then B must evidently drop accurately on A and not beside it. If B drops beside A, which is higly probably, A does not collapse.

 

[Alferd_Packer]

But isn't A conected to B? Aren't both connected to the loads that they are supporting?

 

[Disbelief]

Who suggest that A, B and C are blocks?

You do by not explaining that they are not solid blocks. All you say are subelements A,B and C of equal mass/density. To an average reader, this sounds like you are talking about solid blocks.

The constant of gravity G is about 0.06673 m3/kg s² but is difficult to establish. Nobody knows its exact value. It seems some people mixed it up with gravity force F (= m a) and gravity acceleration g on the surface of the Earth (the latter not being constant as shown above).

You said that gravity was not constant, but then you quote both G and g as constants. So, do you retract your statement that it is not a constant?

 

[X]

1. Right
2. Of course
3. Right
4. Right
5. Right
6. Wrong
7. Not applicable

Imagine three subelements A, B and C of equal mass/density stacked on each other with C on top.

A carries B and B carries C and C carries nothing.

Imagine that C is weakened by fire! What happens to A and B. Nothing evidently because they are not weakened by fire.

Imagine that B is weakened by fire. What happens to A and C?

C may overload B but C and B will not overload A.

Alright, I think I see your problem.
Instead of calling A, B and C "sub-elements, call them lattice structures. Large networks of interconnected elements. And all these lattice structres are stacked one upon the other. And there's more than 3. For the sake of example, let's make 26 of them, A through Z, with A at the bottom and Z on top. Now suppose fire weakens lattice "T". Above T, you have U, V, W, Y, X and Z. When T fails, U through Z falls onto S (along with the collpsed T lattice). Are you seriously suggesting that lattices A through S could support a shock load like that?
It is absurd. The very top of the buildings are not the sections that intially failed.

You missed that? Well if something is going to collapse, e.g. a slender, vertical column A in a building, when something else is dropping on it from above, e.g. another slender, vertical column B, then B must evidently drop accurately on A and not beside it. If B drops beside A, which is higly probably, A does not collapse.

The scenario you proposed is absurd. The WTC buildings were not slender, vertical clumns. They were inerconnected slender vertical columns,
Try making inter-connected lattices from your spaghetti. Use a cross-sectional area to height ratio of 30 for WTC 1 & 2, and 75 for WTC 7. To compare, your spaghetti strand has a cross-section to height ratio of less than 1x10^-3. It will still be ridiculously unrealistic, but nonetheless better thatn your idea of dropping spaghetti strands onto spaghetti strands.

 

[Minadin]

So, your contention is then that "the rest of the structure should have been resilient enough to withstand the impact of those many tons of debris from the impact area and above" then - not that "the structure in the impact zone shouldn't have failed due to fire / impact damage". Is that correct?

Or is it now that "the falling structure and building contents from the floors above should have missed the lower building entirely" or something to that effect? Because if you are arguing that, based on your absurd spaghetti example, you're completely ignoring the floor assemblies and contents of the building by just focusing on the likelihood of a single falling column from above impacting a single column from the lower, previously undamaged section of the building.

That's ridiculous, of course, because that one column isn't falling all by itself. It's coming down along with everything that was connected to it or supported by it. And it's not just impacting the one column, it might hit the column next to it, or the floor assembly to which that column is attached. You have so much stuff falling from above that probably just about everything will be impacted in the lower section.

 

[Cuddles]

The constant of gravity G is about 0.06673 m3/kg s²

Really? You're absolutely sure about that? You don't think you might have it wrong by nine orders of magnitude?

but is difficult to establish. Nobody knows its exact value.

Define "exact". We know it to to about one part in 10,000. And we know mu (G*M) to 1 part in a billion for the Earth. That's pretty exact really. Especially since most engineering tolerances will be around 1%, maybe down to 0.1% in extreme cases.

 

[phunk]

You missed that? Well if something is going to collapse, e.g. a slender, vertical column A in a building, when something else is dropping on it from above, e.g. another slender, vertical column B, then B must evidently drop accurately on A and not beside it. If B drops beside A, which is higly probably, A does not collapse.

If B misses A, it keeps going and hits something lower down the structure, like the horizontal frame members holding A in place.

 

[rwguinn]

If B misses A, it keeps going and hits something lower down the structure, like the horizontal frame members holding A in place.

I think the child is trying to impress with his knwledge of fizicks:
Even molecules are made up mostly of space, therfore, anything hitting anything else is a remarkable co-inkidink.

Notice the excessive attention to the irrelevant details-Universal gravitation constant, etc.
We have here a kid who has yet to understand what is important and what is merely...out there...

 

[peteweaver]

You missed that? Well if something is going to collapse, e.g. a slender, vertical column A in a building, when something else is dropping on it from above, e.g. another slender, vertical column B, then B must evidently drop accurately on A and not beside it. If B drops beside A, which is higly probably, A does not collapse.

What about the floor slabs, and the joints connecting the columns ?

 

[Architect]

No, no!! Can't you see!!! He MUST know the answer because he designs BOATS!

 

[sts60]

2. Yes, steel structure buildings (where the loads are supported by steel columns, spandrels and horizontal beams) do not collapse due to normal fires.

This is simply not true, and this has been pointed out - with examples - in this and other threads. One would think that such an egregious error of fact would not be made by anyone who has spent more than a few minutes reading these threads, let alone anyone who has made any pretense to actually researching the topic.

The sub-items may deform, crumple,sag or bend due to heat, and some local parts may rupture (rarely) ... but the total structure never totally collapse in 1 000 000's of pieces by their own weights and ever present gravity, like an avalanche. Never heard of! Except WTC1, 2 and 7 of course.

The handwaving attempts to create a cloud of qualifiers do not rescue the initial claim above from being flat wrong. Any firefighter can tell you that steel-framed buildings can and do collapse due to fire alone. We have a special interest in that fact because we don't want to get killed by such collapses.

Some of the qualifiers are especially amusing:

"1 000 000's of pieces"! As if quarter-mile-tall, occupied skyscrapers would not collapse in many pieces, no matter what the cause - impacts and fires alone, or aided by bombs, or mrwrongt13's Magic Fusion Putty, or death rays from space.

"By their own weights and ever present gravity"! Which is, of course, redundant - but never mind, somehow we are supposed to be suspicious of weight making a building fall. Obviously the evil gubmint attached rockets to various parts of the towers to make sure they wouldn't accidentally fall up, or perhaps hang in the air Warner Bros. - style.

"Like an avalanche"! I suppose we should think quarter-mile skyscrapers should fall like... a slow drip from a leaky faucet? Like a rain of feathers? (Really, this quote is right up there with MoonMan's characterization (from apollohoax) of the Lunar Module ascent stage liftoff. He was suspicious because "it took off like a rocket".)

 

[Architect]

In view of Heiwa's caims that naval architects are up to speed on the design of building structures, I decided to take a look at the syllabus of a leading UK university course:

First Year​

16 132 Engineering Mechanics
21 103 CADAP
21 131 Introduction to Naval Architecture
21 132 Introduction to Marine Engineering
21 187 Introduction to Marine Transportation
21 188 Marine Applications of Engineering Analysis
MA 111 Mathematics
MA 112 Mathematics ​

Second Year​

21 221 Fundamentals of Marine Vehicles
21 223 Naval Architecture Design Projects
21 224 Marine Manufacturing
21 227 Marine Dynamics and Hydrodynamics
21 237 Introduction to Marine Structures
21 287 Naval Architecture Principles and Practice
NM 201 Engineering Applications for Naval Architects
and Marine Engineers
NM 202 Fundamentals of Marine Engineering
MA 211 Mathematics​

NM 203 Fundamentals of Marine Engineering

21 286 Marine Materials and Design​

Third Year​

21 306 Marine Design
21 331 Resistance and Propulsion
21 362 Ship Design Project
21 370 Marine Business and Financial Management
21 371 Marine Materials and Structures
21 374 Marine Experiments and Analysis
21 375 Ocean Wave Modelling
21 377 Marine Machinery and Control
NM 303 Statistical and Computational Methods for
Naval Architects and Marine Engineers
21 373 Marine Engineering Systems
NM 304 Marine Automation
21 363 Offshore Engineering
21 372 Mechanics of Marine Structures
21 372 Mechanics of Marine Structures
NM 305 Yacht and Powercraft Design​

Fourth Year​

21 444 Ship Power Systems and Design
21 490 Project
NM 403 Seakeeping and Manoeuvring
NM 414 Risk and Reliability​

21 457 Marine Engineering Design

...and so on.

Now, the observent amongst you will have noticed that - as expected - the course covers a very wide range of design an engineering issues. If you plough through the handbook, however, it becomes apparent that an awfully lot of it - nearly all, by all appearances - is Mechanical Engineering.

Nowhere do I see structural engineering for buildings.

Now if I look at the structural engineering syllabus, can anyone guess how many classes they do in the subject? And would you like to guess whether it's less - or more - than naval architecture?

 

[rwguinn]

In view of Heiwa's caims that naval architects are up to speed on the design of building structures, I decided to take a look at the syllabus of a leading UK university course:



...and so on.

Now, the observent amongst you will have noticed that - as expected - the course covers a very wide range of design an engineering issues. If you plough through the handbook, however, it becomes apparent that an awfully lot of it - nearly all, by all appearances - is Mechanical Engineering.

Nowhere do I see structural engineering for buildings.

Now if I look at the structural engineering syllabus, can anyone guess how many classes they do in the subject? And would you like to guess whether it's less - or more - than naval architecture?

Let's be careful not to mount a straw man, here...
As a Mechanical ninjaneer, I am fully aware that during the the last couple of years of College, specialization leads us further afield from one another.
While I submit that "Statics" is "Statics", there is a different emphasis for different fields. While I have *cough* years in the field of lightweight, air, space, and ground-bound mobile structures, and almost *cough* years as an analyst of such structures, and how and why they fail, there are things that you and Newtons Bit know specific to your chosen field that I don't, and I bow to your demonstrated authority.

As a Mechanical Engineer my own self, I could take exception to your obvious anti-mechanism and point out that Sum(F)=0 is the trivial case of Sum(F)=M*x'' +b*x'+k*x, and my weapons system can whup your target!

 

[Architect]

Let's be careful not to mount a straw man, here...
As a Mechanical ninjaneer, I am fully aware that during the the last couple of years of College, specialization leads us further afield from one another.
While I submit that "Statics" is "Statics", there is a different emphasis for different fields. While I have *cough* years in the field of lightweight, air, space, and ground-bound mobile structures, and almost *cough* years as an analyst of such structures, and how and why they fail, there are things that you and Newtons Bit know specific to your chosen field that I don't, and I bow to your demonstrated authority.

As a Mechanical Engineer my own self, I could take exception to your obvious anti-mechanism and point out that Sum(F)=0 is the trivial case of Sum(F)=M*x'' +b*x'+k*x, and my weapons system can whup your target![/spoiler]

I agree fully. There are a number of mech eng folk here with a good grasp of structures.

But what Heiwa is claiming is that is expertise is comparable to those in the appropriate fields, which in itself implies an equivalent level of education. One thing that is clear, looking at the syllabus, is that the structural component of a typical naval arch. course is actually fairly modest and - let me stress this - very specific to marine structures.

Of course if complte failure to grasp the fact that steel is not magically fireproof is a bit of a giveaway that he's not exactly looked into fire engineering either.

I am minded, incidentally, that at Heriot Watt University the design of oil rigs and similar large framed marine structures was taught by Structural Engineers.....

 

[Minadin]

Well, this is the course listing for Architectural Engineers at my alma mater:

BACHELOR OF SCIENCE IN ARCHITECTURAL ENGINEERING

FIRST YEAR
ARCE 103 Intro to Architectural Engineering
PHSX 211 General Physics I
ARCH 100 Architectural Foundations I
ARCH 101 Architectural Foundations II
ENGL 101 Composition
ENGL 102 Composition & Literature
MATH 121 Calculus I
MATH 122 Calculus II

SECOND YEAR
ARCH 200 Architectural Design I
ARCH 201 Architectural Design II
EECS 138 Introduction to Computing (C++)
ARCE 217 Computer Assisted Bldg Design
PHSX 212 General Physics II
CE 301 Statics and Dynamics
MATH 220 Differential Equations
CE 625 Applied Probability & Statistics
MATH 290 Linear Algebra

THIRD YEAR
ARCH 626 Building Technology I
ARCH 627 Building Technology II
CE 310 Strength of Materials
CE 461 Structural Analysis
ME 312 Thermodynamics
ME 510 Fluid Mechanics
EECS 315 Electric Circuits & Machines
CMGT 357 Engineering Economics
CHEM 184 Foundations of Chemistry I

FOURTH YEAR
ARCE 645 Power System Engineering
ARCE 642 Illumination Engineering
ARCE 660 Building Thermal Science
ARCE 661 HVAC&R Systems Design
ARCH 640 History of Architecture I
ARCH 641 History of Architecture II
CE 562 Structural Design I
CE 563 Structural Design II
ARCE 350 Building Materials Science
CMGT 400 Construction Administration

FIFTH YEAR
ARCE 680 Architectural Engineering Design I
ARCE 681 Architectural Engineering Design II
ARCH 642 History of Architecture III

*Bolded courses meet Architect's requirements.

Of course, that doesn't even come close to what the civil engineers take as far as building structures courses are concerned. Being a land-locked state we didn't offer a naval architecture degree, I'm afraid.

 

[Minadin]

Also, I should like to point out that this conversation about Heiwa's credentials would be an ad hom argument, if it were not the case here that Heiwa used his qualifications as a support for his argument. If he were making sound assertions of fact based on verifiable evidence, it wouldn't really matter what his qualifications were.

 

[Heiwa]

Really? You're absolutely sure about that? You don't think you might have it wrong by nine orders of magnitude?

Tell me! What is the constant of gravity G. Only three decimals is required. Note than I use kilograms and cubic meters.

 

[phunk]

Tell me! What is the constant of gravity G. Only three decimals is required. Note than I use kilograms and cubic meters.

0.0000000000667 m³/kg^.s²
ETA: one hundred millionth of what you posted earlier.

 

[Architect]

Note than I use kilograms and cubic meters.

Good for you. I use kilonewtons and millimetres, like most of the construction industry.