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Summary: This article describes in layman's terms and using common sense the structure of the World Trade Center Twin Towers and what happens when the alleged release of potential energy, due to downward, alleged free fall (!) movement and alleged impact of the mass above its supporting columns when buckling, exceeds the strain energy that can be absorbed by the same columns below. These are the official, identical cause and effect of both collapses. The conclusion is that no global collapse of the Towers can ensue under the given circumstances. The reason is, apart from neither free fall nor impact taking place - they are just inventions, that the upper block, with floor area 4 000 m² and its columns, which only occupy 5-6 m² or 0.13% of the total area, is not aligned with the lower structure and its columns at the alleged incidents/impacts! The upper and lower load beraing columns will never meet at any contact! The upper block in fact consists of many weaker parts (floors) that will simply be sliced apart locally by the lower structure and then entangled with and jammed there and the collapse will be arrested. You will learn what a gravity driven collapse really is and why such event does not take place at the WTCs! The subject have been analysed in many articles on the Internet but you find new observations and explanations here? The article is intended for children and amateurs of skyscraper design who want to get a better understanding of the world around us. The information is so simple to grasp that no peer review of 'scientists' is required to support it. There is no mystery about it. The writer is a structural engineer for Heiwa Co albeit in the shipbuilding and very big oil tankers sectors but the principles of structural design and analysis are the same. It is a more detailed description than this paper but the conclusion is the same! The writer once had a plastic garden table with four legs. Guests and the writer BBQued and put a lot of weight on the table (bottles, plates, glasses = weight). And then one guest dropped a plate of grilled steaks on the table (impact) and one leg of the table failed (design fault) - buckled - and the table tipped ... and all the weight shifted ... and ended up on the ground. The other three table legs ... miraculously didn't globally collapse on the dog below the table due to this impact - as they should according to latest NWO physics. But it was before 911. 1. 1 The major Problem - No Evidence of (1) Free Fall, (2) Impact and (3) Shock Wave The major problem is that the authorities suggest that the top part, the upper block of WTC 1 with assumed mean, uniform density 0.18 tons/m3 (very light) above the alleged buckled columns in the initiation zone - no such damaged, buckled, columns have been retrieved from the rubble - drops near free fall (!) as a rigid, solid mass and releases potential energy, PE, and then, after an impact (the PE is now kinetic energy, KE) between the upper, rigid part and the lower non-rigid structure below, perfect alignment is assumed, destroys the latter due to lack of strain energy, SE, there, while all videos of the collapse show that the upper block in fact telescopes into or shortens itself for 2-4 seconds, while the steel structure below is still intact! WTC 2 is similar. The whole upper block of WTC 2 tips over and disappears soon after as shown on below photo. To suggests that the upper block drops vertically and is aligned with the lower structure is a predicament. It is quite clear that nothing drops on the right wall of WTC 2 structure below the upper block, where smoke and dust are ejected ... for what reason? Nothing has impacted the right wall! On the other hand it seems a great explosion has taken place lifting and tipping the upper block to the left! No free fall or impact occurs ... and cannot occur - and none are therefore recorded on any videos!  Gravity is an ever present force of attraction between any two objects, e.g. all the parts of the towers and the Earth. WTC1 and 2 consisted of many parts and, when WTC1 and 2 were intact and all parts were attached to each other, gravity resulted in low, safe compressive stresses in the primary load bearing columns that were <30% of the yield stress as will be shown in 5.1 below. A floor is not a primary load bearing object. It just transmits its weight to the primary load bearing objects. It will also be clarified in 5.1 below. If you cut a primary load bearing vertical column in one location, it cannot transmit any load and the stress in it at the cut becomes zero. If you then cut the same object a bit away, the lose part will evidently drop out and fall down. If it is located in the wall, it is likely it drops down to the ground outside the structure. A core column may fall on a floor or down a lift shaft. In WTC1 and 2 we are told that two times 230-240+ primary load bearing vertical columns simultaneously failed in two locations in an initiation zone ... and disappeared allowing free fall. I do not believe it, because it is a crazy idea and not observed, but let's assume it anyway so this article can describe the madness. What happens then? Well, if the upper block above the initiation zone was then hanging in a crane and slowly lowered down and placed on the lower structure, the lower structure would evidently carry the upper block ... as before. The columns would again be stressed to <30% yield stress. But there was no crane lowering the upper block! We are told that the upper block (it is assumed a rigid, solid mass with uniform density!) (1) near free falls vertically and (2) impacts instantaneously on the lower structure, i.e. its columns, and (3) causes a shock wave in the lower structure columns, the latter are overloaded and ruptures in 1000's of pieces, while (4) the upper block remains intact during the complete destruction (!!!???), and is (5) compressing the rubble below and (6) remains intact on top of the rubble and (7) then self-destructs! These are very misty allegations - actually inventions. It is the first time in history, when a smaller object - the light weight, upper, actually non-rigid, flexible steel structure consisting of many smaller parts - destroys the bigger and stronger other object - the complex steel structure below only with assistance of gravity. The upper blocks of WTC1, 2 are the problems. They are according Bazant/Seffen, two scientists, findings of which will be further analyzed below, supposed to be rigid, stiff, solid, of uniform density, indestructible, etc., in order to first near free fall vertically, then impact and finally drive two global collapses of intact steel structures that have never been seen before and after 911. The weights of these upper blocks were not massive! The weights just compressed the structure below to <30% yield stress. And the load bearing structure/columns below only occupied 0.13% of the total foot print (WTC1 at the initiation zone - the rest was air!), which is an indication how strong the lower structure columns were! So there was plenty of space/volume for other structure, e.g. floor, to get entangled in, which is completely ignored by the authorities. Early on the so called pan cake theory was suggested - whole floors dropping down - but it was soon abandoned. NIST cannot then explain the WTC lower structures total collapses except that PE = KE (of upper block) > SE (of lower structure) (NIST's law), that will also be further described below. Complete nonsense as PE/KE of the upper block has nothing to do with SE of the lower structure! Bazant and Seffen came to assistance. But they assume that the load bearing structure columns occupy 100% of the total foot print due to uniform density of the whole block above and not only 0.13% due to local, concentrated strength. They also assume that there are no space and volume for entanglement of locally failed parts and that collapse arrest may occur! Collapse arrest will be defined and explained below in paras. 1.2 and 1.5. 1.2 Missing Evidence - Why wasn't the upper Block sliced in two? There are 1000's of photos of the collapses but unfortunately some are missing, e.g. those during the 0.8 - 0.9 seconds, when the indestructible upper blocks start to near free fall (1) 3.7 meters - all columns failed - and then collide/impact (2) with the structure below transmitting the total upper block KE to the structure below. It is then that the clock of collapse time should start and (3) the shock wave is transmitted. It can evidently not be seen. No intact upper block (4) is seen either during the destruction that followed. In the case of WTC2 the upper block explodes outside the footprint of the tower. But if there is no free fall and no impact and no sudden transmission of KE, then a gravity driven collapses cannot even be initiated and no collapse time clock will start. Any calculations about what happens after the alleged impact and instantaneous transmission of KE become then pretty theoretical. We are told that PE is released at (1) and becomes KE at (2). NIST suggests in its infamous 10 000 pages report that the PE or KE (no calculations) exceeded the total strain energy, SE, of the structure below (no calculations), or PE = KE > SE, but it is nonsensical maxims employed by savages! PE/KE and SE have nothing to do with each other! Nothing to do with each other? Exactly. The PE/KE of the upper block must evidently be applied at a sudden IMPACT to the structure below, but gravity does not work like that for loose objects! If some PE/KE of the upper block is applied to the lower structure, you may, e.g. expect some local failures due to lack of local SE as long as the load is applied. The load will then slip off due to the deformation. The SE of the complete structure is something completely different. Then there is the lower structure itself - it can evidently destroy the upper block, if it gets loose. The upper block that allegedly became loose consists of 280+ vertical primary load bearing objects - the flexible columns - holding it together. All the loads of the masses above are only held by the columns. In order for this upper block, 4 000 m² floor area and a certain height, with 280+ columns that occupy only 5-6 m² of it (<0.13% of the foot print), to free fall, impact and overload the lower structure, it must be 100% aligned with all 280+ columns below. And then, if the 280+ columns above touch the 280+ columns below at contact, they must not slip off! Otherwise no KE will be transmitted! Each column has failed at two locations and the intermediate part has disappeared or is bent 180°. Does anyone believe that the cross surfaces of the broken parts are identical allowing a perfect fit at impact ... and overload? Try to hit a nail with another nail and see what happens because each column has the function of a nail hitting another nail! Evidently, the upper block columns were not 100% aligned at (1) with the lower structure columns - we are told that they were bent - and therefore they will miss the lower structure columns at (2). No impact, no shock wave! And therefore no global collapse due to KE > SE. If you argue that it was only the lowest floor of the upper block that first impacted the uppermost floor of the structure below, you should know that the PE of the lowest floor is negligible (5%) compared to the total PE of the upper block. The KE of the lowest floor must then be transmitted, via the uppermost floor of the lower structure (actually the bolts at the columns), to the columns to affect the latter. You require local SE for that! A vertical impact on a floor cannot be transmitted via the same horizontal floor to the supporting columns and break the latter. The connections between the floor and the column break first! And something else should happen: 1.3 What you would expect to happen If something falls it must go down freely. No upper blocks are seen going down freely. They disappear early in the action that follows! Or that 240-250+ columns suddenly fail just prior that. And then there is this mysterious impact after falling down 3.7 meters near free fall that is not observed. The columns occupy only 0.13% of the total cross area and, if misaligned by say 10-40 mm, they will miss or slip off the columns below = no impact. And if there is no impact, there is no transmission of energy, KE, to the lower structure - only weak, thin horizontal floors of upper block and lower structure will be cut/punched/sliced by vertical, strong columns that will remain virtually intact. So let's assume the upper block gets lose (A), is misaligned (exaggerated in picture below) outside the lower structure on two wall sides and inside on the two other wall sides of the lower structure (B) and goes down (C). Similar misalignment takes place at the core.
The upper block walls columns (right in picture (C) above) misaligned on the inside of the lower structure will now slice through the first (red) floor below the impact zone - the floor hinges down on the (red) floor below - while the upper block walls columns (left in picture (C) above) misaligned on the outside will drop in the air and hit nothing! Actually only half the mass/walls of the upper block carried by the walls participate in the local failures that follows and results in tilting of the upper block. On the other hand the lower structure columns (left in (C) above) on the inside of the upper block will slice through the first (green) floor of the upper block - and it hinges down too on the (red) floor below! You do not need much energy for that. And the lower structure walls columns on the outside of the upper block (right in picture (C) above) will remain ... intact! Similar floor failures may occur at the core but there the columns are fewer and spread around and interconnected by horizontal beams to which the floors are bolted. In (D) the upper block right wall columns inside the lower structure are assumed to have sliced three (red) floors in the lower structure and these floors have hinged down with two (green) floors of the upper block that have also been cut by the strong wall columns of the lower structure inside the upper block on top. Similar failures take place at the core. Evidently this destruction pattern will tip the upper block against the intact (right in (D) above) wall of the lower structure and the upper block will be jammed. The progressive collapse is arrested. This more logical local collapse pattern is something NIST never considers. If the collapse is not arrested, the upper block will disappear completely into the lower structure (E) and the left wall of the upper block will fall down in one piece to the ground! The upper block green floors however remains inside the top of the lower structure. And we do not see that on any videos 1.4 Why Global Collapse will not occur (in Layman's Terms) What a reasonable person would expect after local failures at the initiation zone - even very serious ones - is that gravity would just slowly (no free fall) pull the upper block assembly down, some parts may contact each other and get damaged like in a soft collision, and after that primary and secondary structure of upper and lower parts would get entangled into one another. Some parts will fall down outside the building. This is the basic reason why a multi-parts steel structure does not ever globally collapse like a house of cards! Or in other words: There are many masses that drop - connected to one another one way or another forming an upper block. You cannot simplify and say the upper block is only one solid, rigid mass. There are four outer walls, core columns, many floors, etc. Let's say that the numbers of masses of the upper block are n. If these masses drop, their PE becomes KE. Each mass, numbers 1- n, has its own PE/KE due to gravity. And each mass starts at a different location and will drop on a different location by gravity. The lower structure of WTC1 is fairly complex - 280+ columns, 94 floors, etc. It cannot be treated as one spring or a party balloon or similar. The columns only occupy 0.13% of the total cross area of the tower. What loads are applied on them at an impact? Probably none as they are small and any load will slip off. The uppermost floor of the lower structure thus occupy 99.86% of the cross area. What loads are put on it and where and when? There are many masses, numbers 1- n, dropping down. Which one will be applied first? Right - the one that was closest above and will actually contact something below. The strength of the upper block and lower intact structures (all parts/connections, etc) are known. We know the various loads, numbers 1 to n that are dropped on the uppermost floor of the lower structure in a certain order depending where they started from. It should be clear that if a column impacts a floor, the column will only punch or slice a hole in the floor. 1.5 Analysis of Collapse Initiation, Progressive Collapse and Collapse Arrest - The Masses get entangled In order to analyze the collapse initiation you evidently apply the loads to the lower structure and see what happens! Does global collapse start or is it just local failures and global collapse is arrested?
So we start with load number 1 - the one that is applied first! This is a repeat of 1.3 above. The analysis will be based on observations and using common sense. What happens to the uppermost floor of the lower structure being loaded by load no. 1? And where does load no. 1 come from? In (C) above it might be the wall columns and core columns/horizontal core beams of the upper block that hit the uppermost red floor of the lower structure in certain locations. Any deformations? Local failures? Is the poor floor still connected to the 280+ columns? Maybe it is only sliced locally and falls down as shown. Then we apply load number 2. This is the lowest green floor of the upper block that hits the wall columns of the lower structure on the other side and core columns/horizontal beams of the lower structure. The green floor of the upper block has no chance here! It is sliced and drops down on the red floor below. It seems the big load of the upper block is only applied on the - weak - side of the lower structure - only weak red floors in the way there, while there is more opposition on the other side - lower structure columns slicing up the green floors of the upper block. Does anyone believe that the upper block will fall vertically - near free fall - under the shown circumstances - which is the fundamental assumption of Bazant and Seffen? Progressive collapse has however started! Thus we have to see what happens at the next floors above and below applying all the n loads there in proper order. The first collapsed, hinged floors above and below will probably deflect many of the loads coming first and later from above outside the structure or inwards, against each other causing jamming and entanglement of these loads/masses. Too complicated to calculate? Not really. As long as you realize that it is not one, solid, rigid mass (one PE/KE) that impacts one structure below with one SE (?), you will agree that the Bazant/Seffen/NIST simplifications described below are just irresponsible nonsense. The first loads/masses from above, i.e. columns of the upper block applied on the uppermost floor will probably locally damage the uppermost red floor of the intact structure either at the boundaries or on the floor itself. The horizontal floor then becomes sloping in various locations and positions. It does not drop flatly down. The first loads/masses will then change direction from vertical to sideways due to the sloping floor parts and be stopped, e.g. entangled in the strong vertical columns. Gravity works like that. Some loads may drop further on the next floor, but the latter will obviously resist or only fail locally, where the particular loads/masses are applied! The next loads/masses coming dropping from above, e.g. the first green floor will not hit the uppermost red floor, but something else, i.e. the vertical columns of the lower structure and the upper block. There is a lot of damping, friction, etc. in this mess apart from pure SE of the floors of both upper block and lower structure resisting and deflecting the loading. The second uppermost red floor of the structure below - see (D) above - may also collapse, similar to the uppermost floor, when the masses, i.e. the columns above have dropped on the first load/mass/mess. Progressive collapse continues. The second red floor of the structure below, now also sloping, will in turn deflect the loads from above as the first. Then the second green floor of the block above will be damaged, when it drops on the columns below. After a while the top part of the lower structure is completely jammed with damaged floors of the upper block and the lower structure sliced apart in various locations. The remaining mass will then not do much further harm. Some will drop down outside. The rest will remain on top, as if lowered there by a crane. If the whole upper block is sliced up by the lower structure (E) before arrest, the upper block outside walls will drop down on the outside but all the upper block (green) floors will remain up top jammed in the lower structure. The collapse is arrested! This is the beauty of an airy tower steel structure of non uniform density with a strong perimeter held by spandrels. Some local parts my fail (e.g. floors) due to gravity overload and then any other loose parts just get deflected, entangled and jammed in the mess, as there is plenty of volume and intact structure for that. A stable state of a partially damaged structure has developed. No global collapse will ensue. Collapse arrest is when a stable state of a partially damaged structure has developed. NIST in its 10 000 pages report does not mention collapse arrest as a more logical result of local failures and the report is thus incomplete. 1.6 What really happened? So why did the columns of the lower structure blow up in 1000's of pieces, if there were no impact and shock wave? The answer will be given at the end of this article. The upper block it seems to be destroyed before it reaches the steel structure below ... at zero velocity ... and does not impact! It is mostly air anyway! The following photos extracted from a video explain what happens: 
The destruction of the upper block - it is compressed 20-25 meters - before its columns reach or, as suggested, impinge on the intact columns of the structure below simply means that the upper block is not rigid and that its potential energy is split in 1000's of small parts and that the upper columns cannot impact on the columns of the solid intact tower steel structure below and destroy the latter. It also confuses the total collapse time of WTC1! When does the WTC1 'collapse' actually start? When the roof (and mast on top) starts to displace downwards? At that time no visible damages are seen at floor 94, so you should wonder why the roof moves at all. One second later? The roof has dropped a couple of meters and still no impact and damages are seen at floor 94. Two seconds later. The roof has dropped 10 meters and still no damages are seen at floor 94. Three seconds later. The roof has dropped 20-25 meters and still no damages are seen at floor 94! The columns are still intact at floor 94. There is no free fall or impact! It would appear that NIST, the US authority responsible for analyzing the collapse has abandoned the original suggestion of a rigid upper block free falling, impacting and causing a shock wave and instead suggests that 6-11 lower floors inside the upper block suddenly dropped down and overloaded the uppermost floor of the structure below. The above pictures evidently do not support such modified claim, where it is seen that the roof displaces 20-25 metres while there is no visible effects at and below the initiation/impact zone at floor 94 (where the floors of the upper block are supposed to drop down). If only internal floors suddenly dropped down, evidently the roof would remain in position.
2.1 The false Theory and the misleading Assumptions An American professor Z P Bazant published soon after the WTC collapses 911 a theory that was adopted by the authorities as true. The Bazant analysis is that if prolonged heating caused the majority of columns of a single floor to lose their load carrying capacity, the whole tower is doomed. Bazant suggests that there are five stages until the doom as illustrated by Fig.1 of the Bazant paper!
Note the emotional words used and that upper block is assumed intact and aligned with the structure below. Stage 4: The vertical impact of the mass of the upper part onto the lower part applies enormous (sic) vertical dynamic load on the underlying structure, far exceeding its load capacity (sic), even though it is not heated. Note that upper block is still assumed intact and aligned with the structure below. Evidently not seen on the video pictures above, where nothing happens there, while the upper part is compressed. Stage 5: This causes failure of an underlying multifloor segment of the tower, in which the failure of the connections of the floor-carrying trusses to the columns is either accompanied or quickly followed by buckling of the core columns and overall buckling of the framed tube (i.e. the wall columns), with the buckles probably (sic) spanning the height of many floors, and the upper part possibly getting wedged inside an emptied lower part of the framed tube! The buckling is initially plastic but quickly leads to fracture in the plastic hinges. Note that upper block is still assumed intact and aligned with the structure below. Stage 6 (Collapse): The part of building lying beneath is then impacted again (sic) by an even larger (sic) mass falling with a greater (sic) velocity and the series of impacts (sic) and failures then proceeds all the way down. Are any further impacts seen on of the videos? The upper block must then still be assumed intact and aligned with the structure below all the time to end of collapse. The extra mass below is all rubble! Can it really impact again? Most assumptions and conclusions in stages 1-5 are not correct and the Bazant dramatic stage 6 is not possible. More ... There is no time table in the Bazant analysis and no explanations why the roof drops and the uppermost part of WTC1 above floor 100 disintegrates 3 seconds before Stage 3, floor 95 hitting floor 94, is supposed to take place, the latter never seen on any videos. To assume that the upper block is intact and aligned with the structure below during the complete collapse is not serious. Actually, the upper block, intact, rigid and of uniform density at start of collapse, should according to Bazant's theory remain INTACT after the global collapse at end of Stage 6 ... on top of all rubble the upper block has produced of the lower structure. Nothing could destroy a rigid block of uniform density - not even the final impact with the ground forgetting that the rubble is there to dampen the final impact. The lack of the block above on top of the rubble after collapse proves Bazant wrong.
3.1 Tower Structure - a Bird Cage The structural design of the World Trade Center Twin Towers is very simple as its very lightweight steel framework is similar to a box shaped bird cage in which human beings are working. Most skyscrapers or office towers in the world are built according similar principles. None has ever globally collapsed in seconds before or after 911 except WTC 1, 2 and 7. More ...
4.1 Collapse Scenario and Cause of Collapse - buckled Columns - Lack of Evidence From NIST report - NISTNCSTAR1-6D chapter 5.2 - we learn: "The aircraft impacted the north wall of WTC 1 at 8:46 a.m. … between Floor 93 and Floor 98. … The subsequent fires weakened structural subsystems, including the core columns, floors and exterior walls. The core displaced downward … At 100 min (at 10:28:18), the north, east, and west walls at Floor 98 carried 7 percent, 35 percent and 30 percent more gravity load loads … and the south wall and the core carried about 7 percent and 20 percent less loads, respectively., … At 10.28 a.m., 102 min after the aircraft impact, WTC1 began to collapse. … The release of potential energy due to downward movement of the building mass above the buckled columns exceeded the strain energy that could be absorbed by the structure. Global collapse ensued." From chapter 5.3 we learn: "The aircraft … impacted the south wall of WTC 2 at 9.03 a.m. … between Floor 78 and Floor 84. … (9:59 am) … The release of potential energy due to downward movement of the building mass above the buckled columns exceeded the strain energy that could be absorbed by the structure. Global collapse ensued." Note that the two Towers collapsed for exactly the same cause: The release of potential energy due to downward movement of the building mass above the buckled columns exceeded the strain energy that could be absorbed by the structure. If the column does not deflect or crumple up, there is no downward movement of the mass above and thus no release of potential energy. And no impact! More ...
5.1 Arrangements at Floors 94-98 of WTC 1 Let's look at WTC1 and floors 94-98 - the initiation zone. Total area of each floor is about 4 000 m². The total mass of the upper block is as follows:
The mass above the core is only13 200 tons supported by the 47 core columns with total area 2.1 m². On average each core column carries abt 280 tons so the average compression is 629 kgs/cm² or 63 MPa or 25% of yield. More ...
6.1 The Towers were built very strong in the 1960's The above is a clear indication how the Towers were originally built by serious architects and engineers in the 1960's. Compressive static stresses in the columns were less than 1/3 of the yield stress of the steel before (obviously) ... and after serious damage (not so obvious but shown here)! The buckling stress of the column is virtually the same as the yield stress as the columns were arranged with spandrels. One reason why the static stresses were so low was that the designers had no access to computers to optimize (slender down) the construction. Manual calculations were done and to be on the safe side you added steel and built strong! And steel was quite cheap at that time. And US steel was good quality. The assumed yield stress 248 MPa was probably much higher in reality. NIST never checked the yield stress of the steel from the initiation zone in the rubble! There was therefore plenty redundancy. A plane may crash into the bird cage and nothing happens. A big fire may break out and nothing happens. Why? Because the normal compressive stress in the supporting vertical structure is so low and if any column breaks or buckles, its load is transmitted to adjacent columns via the spandrels and the stress in adjacent columns increase a little. No global collapse is possible under any circumstances. Evidently the columns got stronger (thicker plates, steel with higher yield stress) further down when the 'mass above' increases, but it is certain that the compressive stresses in the Towers never exceed 1/3 of the yield stress. Same applies for the buckling stresses. More ...
7.1 No Release of potential Energy due to downward Movement - Influence of Heat The mass/load above a column evidently compresses it. The column acts as a spring. As long as the compressive stress is less than yield stress, the compression is elastic and hardly noticeable. As seen above the actual compressive stresses were only <30% of yield stress and it is assumed this was common practice in steel tower construction in US and elsewhere in the 60's. How is the yield stress of steel affected by heat? In this writer's opinion it is not affected very much at about 500°C. This is confirmed by any fire test - the test chamber and what's in it never collapses due to the heat inside up to 1000°C. The heat inside is normally by kerosene set on fire. Applied to WTC1 what you would expect due to a fire around the core columns is that they only compress and that their cross areas expand due to heat and the downward movement of the core is a few centimeters! It may put some extra tension in the floor trusses and their bolted connections pulling the perimeter walls inwards a few centimeters - and that is all! The wall perimeter columns, 80% of them are intact and free of soot and marks of fire as shown on many videos and subject to little heat as they are cooled by fresh air, will then further stabilize the core. NIST does not calculate the amount of potential energy released due to downward movement in their report, which is therefore incomplete. The simple reason is that no potential energy is released. In fact, no downward movement of a mass above is even possible due to heat inside the cage and there should be no sudden release of potential energy. But let's assume that potential energy is released vertically as all low stressed columns wall/core collapse simultaneously and are removed allowing a free drop. When 33 000 tons of mass above in WTC1 falls down 3.7 metres due to gravity and crushes all the columns abt 340 kWh of energy is produced by gravity and a fair part of that energy is consumed to crush the columns. It is in fact a very strange release of potential energy due to alleged downward movement of a mass above! The wall columns at the initiation zone did not buckle, deform or crumple up, when the mass above (the roof) has allegedly been falling down for 4-5 seconds. In order to establish what happened to WTC1 we need to know two times for two events that allegedly occurred: the time Tcause, when the potential energy was released due to all columns in the initiation zone collapsing simultaneously, i.e. the time of the cause of the disaster, and the time Teffect when this energy was applied to the structure below at an impact, i.e. the time of the effect. NIST and Z P Bazant do not advise these times. NIST and Bazant talk about an upper solid, rigid block above the initiation zone that suddenly falls down as a hammer and causes global collapse! There are many videos of the WTC1 incident but NIST and Bazant never show us the famous upper block at times Tcause (hammer/upper block starts to fall) and Teffect (hammer/upper block hits)! You wonder why NIST and Bazant cannot show us in their reports a time table for the 33 000 tons upper block and its potential energy first initiating and then producing global collapse. It seems that the upper block is disappearing (sic) at Teffect and a few seconds later before global collapse of the structure below starts. There is no evidence that an impact between upper and lower columns occur! More ... While reflecting about this lack of easy to understand photo evidence in the official reports and university papers,
The purpose of the model test is to establish the stiffness of the table leg pipes (the columns of the initiation zone) under heat and to see if suddenly, at, e.g. temperature 500° C, the mass above (luckily most water in this test for children) drops down, at a significant speed and with an enormous kinetic energy, and impacts on the cement floor with an enormous dynamic load. Or does nothing of that sort happen? Maybe the table legs will just bulge. You will find out (the latter)! More ...
9.1 Elastic Strain Energy absorbed by primary Structure below and its Compression It should thus be clear that the only primary structure below our wall cage bars are the wall cage bars and it is very easy to calculate what elastic strain energy they can absorb before plastic deformation and rupture when any of them is compressed above 30% of yield stress. The total strain energy our wall and core columns and attached spandrels and floors can absorb is evidently the energy required to first strain them to 100% yield - the elastic strain energy - and second to buckle or rip them apart - the buckle or rupture strain energy. In order to rip a column apart, the stresses in the structure must exceed the rupture/break stress of the steel that is much higher than the yield or buckling stress. This compression is evidently in the elastic range of the 'spring' and takes place when it is completely unloaded! Another 'expert', K. A. Seffen, in a paper 'Progressive Collapse of the World Trade Centre: a Simple Analysis' suggests that the potential energy released by the mass above - the upper block - resulted in dynamical "over-loading" of the undamaged lower columns by a factor of 30 (!) compared to their static load capacity at impact and transmits it to the structure - 'spring' - below and shakes it into pieces. How is that possible?
How the uniform density ro behaves between t = 0 and t = t(end) is also a mystery. It is evidently assumed constant in the rigid upper block and lower, intact part, but what about density ro of the intermediate block bL? Apparently the original uniform density ro increases in the bL part according Seffen during collapse - to another uniform density as a function of time - a new phenomenon! Photos of the WTC collapses show that material, dust and smoke are pushed outwards at high speed of the intermediate block, which is not explained by Seffen. There can not be any uniform density of any type in this area of damaged core columns and falling off walls. Thus - during collapse according Seffen a rigid upper block lL floats on a mysterious intermediate block bL of broken, compressed material with a uniform (?) density that increases >600% with time that in turn floats on the lower, intact part below a strange crush front. It is quite magic actually and could only have been invented by a blind scientist in an ivory tower. No mention that the columns must be perfectly aligned. These are the false assumptions of K.A. Seffen! That (1) the tower has uniform density ro, while it is not uniform at all, (2) the upper block begins to accelerate downwards as a rigid undamaged body with uniform density ro= 0.18 ton/m3, while it is seen to self-destruct, (3) that the initial load imposed onto the structure beneath was exceptionally high, while it was only that of a big bale of cotton, and (4) that the damage, no new damage seen of course in the smoke, was bound (??) to propagate. Alignment of columns is conveniently forgotten. You wonder what kind of structure bL is? Solid? No! Damaged? Yes! How is the upper block connected and aligned with the undamaged structure below via the mysterious structure bL zone? As shown in 7.7 the upper block disappears, implodes before it even reaches the floor below to impinge it, and, if it impinged, it should only bounce! But according to Seffen the upper block drives the collapse. You need kinetic energy, KE, for that and it can only be provided by an intact, rigid, uniform density upper block that remains intact, rigid, with uniform density during the whole destruction of the lower structure. The upper block is the only part that can provide KE during the alleged global collapse. The lower structure does not add any extra KE to the collapse or contribute to the collapse - it is being destroyed (lack of strain energy according NIST). Actually, the upper
block, intact, rigid and of uniform
density at start of collapse, should according to
Seffen's theory also remain INTACT after the
global collapse ... on top of all rubble the
upper block has
produced of the structure
below. Nothing could destroy a rigid
upper block of
uniform density - not even the final impact with
the ground forgetting that the rubble is there to
dampen the final impact. The lack of the
upper
block on top of the
intermediate block
bL
rubble after collapse proves Seffen wrong. That is one reason why there is no figure of
final collapse in Fig. 4 above! It should evidently
show the upper
block on top of the rubble of the
intermediate block
bL
then resting on ground as in figure
left! You can easily calculate the uniform density
of that rubble
heap! The only gravity driven collapses known to mankind are snow or soil avalanches (or similar), i.e. an upper block with uniform density of snow/soil that gets lose on a slope due to the gravity force exceeding the friction between the upper block and ground. In spite of its low uniform density the upper block is pretty stiff during the collapse that starts at an initiation zone in the snow. Then the upper block releases potential energy and pushes a lot of snow in front of it (same density as the upper block) that piles up and compresses in the crush zone (density is increased there but the strain energy is small - snow flakes!) until it runs out of potential energy ... and the upper block is compressed. Evidently lose snow is thrown up in the air, when the crush zone advances down the slope. Such a snow avalanche has nothing in common with the WTC1 collapse, even if the upper block of WTC1 had a uniform density similar to that of compressed snow (180 kgs/m3) that sticks together - snow crystals interacting. But this is what the authorities and university professors want us to believe. More ...
10.1 Elastic Strain Energy of the Mass/primary Structure/Block above NIST or Bazant or Seffen does not consider the elastic strain energy of the primary structure and attached masses above or the upper block. It is in fact another 'spring'! It consists of a number of solid weights - the floors - connected to columns - each a 'spring'. Such a contraption is evidently not rigid or solid as assumed by NIST, Bazant and Seffen and in the unlikely case that it actually drops down free fall on a structure below, it will only transmit a sequence of energy pulses divided by finite times, each of which cannot overload the structure below. Furthermore, this upper block multiple 'springs' contraption is not very solid. It implodes before it can do any harm! More ...
NIST, Bazant and Seffen suggest that the mass above, the upper block, acts as a rigid, solid hammer (and not a spring) that multiple hits and/or stays in contact with the structure below - the nail - even if it is not evident from any pictures above - the upper block disappears before global collapse starts!
In the writer's view the picture above looks as if a bomb has hit the tower with enormous energy, structural joints vaporize and mass murder is committed (but that is beside the topic of this article). And where did the upper block go? More ... This means that we can conclude the following: 12. Conclusions The Twin Towers structure was very simple and its primary structure wall and core columns can be likened to steel bars in a bird cage full of air ... and humans. The compressive stress in the bird cage bars due to mass incl. floor loads is very small (<30% of yield stress). The Towers' structure was very strong! You can heat up the bars under compression in the cage to, say 500°C, and nothing dramatic happens and particularly not that the bird cage suddenly collapses in 1000's of pieces. The stress in a 500° C heated column may increase to 40% of yield. It will not buckle due to that. As soon as the fire moves away to another area the column cools again. Local deformation may take place. But in this article we assume that the upper block gets detached and suddenly falls down on the bottom part; release of potential energy. NIST has not produced any "buckled" columns of the initiation zones, be it bent 180° or crumpled up, that would have produced downward motion and release of potential energy. We are talking about 566 columns that must have "buckled" for the effect ... and none is presented as evidence that potential energy was released for that cause. But it is assumed here anyway.
Reason why a steel building cannot collapse due to release of potential energy is, in simple terms, that the potential energy will mainly be applied to secondary structure - the floors - that will be overloaded and detached from the primary structure - the columns! The potential energy will then be deflected and will not be applied to the primary structure ... that will remain intact! The collapse is arrested. That is one reason why there are no figures of final collapse in Fig. 1 (Bazant) and Fig. 4 (Seffen) above! It should evidently show the upper block on top of the rubble then resting on ground! Nothing could destroy a rigid block of uniform density - not even the final impact with the ground forgetting that the rubble is there to dampen the final impact. The lack of the upper block on top of the intermediate block bL rubble after collapse proves Bazant and Seffen wrong. It is kindly recommended that NIST, Z P Bazant and K A Seffen correct their reports and make an improved timetable, analysis and explanation why global collapse as shown in the forensic evidence actually ensued as the proposed sequences of events and causes do not tally. Do this for the sake of your children. And tell us ... what happened to the upper block! Anders Björkman, M.Sc. Heiwa Co, Beausoleil, France - April 14, 2008 (The above article is still being developed, corrected and improved and comments are always welcome). A more detailed analysis of same sort is by Mark H Gaffney and recommended for the advanced reader. If you ask what started the fire in WTC1 you should look here! And another video of the end of WTC1 is in the end of this video!
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