Part of the confusion , imo, results from the conflation of initiation events with progression. Initiation of collapse sequence DOES involve column buckling. If nothing else illustrates this, the perimeter column inward bowing/creep does.
Agreed. Initiation was primarily a consequence of column failures. Whereas during progression columns were effectively bypassed - certainly for the perimeter and near certain for the core. "initiation" for "Twin Towers was without doubt a cascade failure AND essentially 3D. Two points about that statement:
1) It matters not whether there was or was not a "CD" contribution - it still was a 3D cascade. THEN
2) The biggest limitation on thinking - both sides - is inherent "1D" premise assumptions. Recall some of my "bleeding obvious" comments on two examples. "Missing Jolt" and the more generic debates about whether or not tilt would cause/prevent axial contact of the falling upper part of column.
Pure misapplication of Bazant's "falling start" limiting case assumptions. What caused "tilt" was failure of columns. More failed on the low side than on the high - hence that side got lower - hence "tilt". AND for that to happen the top end and bottom end of each failed column were closer together than they had been before failure. And (this is where I usually take a short cut) The ends had
already moved past the point where axial impact was possible. Too late for the impact.
(That is not entirely why it is 3D rather than 1D but I'll leave it there - "cascade failure" CANNOT be explained in 1D ergo anyone trying to explain cascade in 1D will get it wrong.)
Put simply once tilt has occurred the scenario for axial impact of column ends is already gone. (There are IIRC three "yes buts" - all easy to dispose of so I'll leave the bare assertion stand.)
And "Missing Jolt" is merely a specific sub set of that broader logical error. In context of this current discussion T Szamboti tried "mix and match" - took the "falling top bit" of the Bazant abstract limit case model and literally applied it to a "real world" explanation. Doesn't work. but, more important, look how many took him on without questioning the false premises...all that wasted research looking for a big jolt which never could have been.
AND - it is setting the scenario .. no amount of math or FEA will correct the error of logical false starting point. That's part of the reason why a lot of detail focus engineers miss the point - forest v trees syndrome. Or rather alligators and swamps. That is better but not a perfect analogy - but...let's not derail.
Even then, the single last failure before collapse "release" could well have been a floor failure....
Could be - I've never considered it - cannot deny it.
...Again my humble opinion, but its the frustrating rise of what I term "binary thinking", that contributes to this greatly. The reasoning , if thats what we can call it, goes like this:
Columns failed at initiation therefore columns failure continued.
You refer to this as simply not thinking.
Yes. Recall my specific concern with "do not think" OR "cannot think" is integration of multiple factors into a coherent hypothesis. Most truthers - most truther claims - are about "single issue anomalies" which the truther cannot put into any sort of context. So reverses burden of proof to get us debunkers doing the thinking...
...ROOSD makes little sense to the binary thinker. Columns hold buildings up, therefore collapse must involve loss of columns. Floors don't hold buildings up therefore floor loss means nothing. Therefore only column loss could be responsible for collapse.
could well be a factor. My couple of recent posts in this thread directed at getting some base factors clear - not adding in more subtleties. The recent confusion mostly about losing the objective and forgetting the basics. Arguing about "my alligator had teeth before yours"...and forgetting "drain the swamp" - same disclaimer as previous for that analogy.
...Of course columns did fail during progression, but that was not the primary driver of progression. Column loss came after, and as a direct result of, floor losses.
Without doubt. And the value of M_T's OOS model was that it opened debate here when confusion of "real world" v "Bazant" was rife. Despite several members disagreeing with me. Read the start of this thread. And the "Applicabilty of Bazant..." thread.
That is another problem for the binary thinker. To them, collapse was strictly a top down floor by floor sequence. To them , envisioning floor collapse means a whole floor space collapsed at once, then another one, and columns failed at the same time. The "clap clap clap" nonsense of some years ago is a good demonstration of this.
In fact floor collapses led perimeter column peel off and core column Euler buckling
AND
was not likely ever an entire floor space falling all at once.
And that is one aspect where Major_Tom's excellent research is valuable for those who have a need for it. He has done work on "zonal collapse" - cannot remember exactly how he defined it. And everyone please note before you tear my head off. I referred to Major_Tom's technical
research. Not his offensive style of posting or his persistent errors of logic. I ignore both.
The so called "squibs" demonstrate not only that floor failure was leading perimeter peel off, but also the variable location of the leading part of floor collapse.
Sure. and the "variability" does not change the principles. Similar reasoning to why I generally ignore "tilt" in arguing the transition from "initiation" to "progression". The tilt doesn't change the broad issues EXCEPT where the truther side claimant is confused by things like "how did it not topple" OR "how did it get back inside the lower tower" etc etc
Imho of course. I could be wrong.
Not likely - seeing you are mostly singing the same tune as me.
)
