- My Forums
- Tiger Rant
- LSU Recruiting
- SEC Rant
- Saints Talk
- Pelicans Talk
- More Sports Board
- Fantasy Sports
- Golf Board
- Soccer Board
- O-T Lounge
- Tech Board
- Home/Garden Board
- Outdoor Board
- Health/Fitness Board
- Movie/TV Board
- Book Board
- Music Board
- Political Talk
- Money Talk
- Fark Board
- Gaming Board
- Travel Board
- Food/Drink Board
- Ticket Exchange
- TD Help Board
Customize My Forums- View All Forums
- Show Left Links
- Topic Sort Options
- Trending Topics
- Recent Topics
- Active Topics
Started By
Message
1
Posted on 9/12/22 at 7:49 pm to Indefatigable
quote:Both doomed. All that was needed were a few column failures and it would just zipper down the structure. Think standing on a coke can and plucking it.
Any other engineering folks are also welcome to opine.
Do you think the collapse of the North Tower (first hit, higher up) was inevitable from the moment of impact, or could it have remained standing had the South Tower not been subsequently hit and collapsed next door? In other words, what impact did the South Tower’s collapse have on the North Tower’s structural integrity, if any.
Posted on 9/12/22 at 8:02 pm to Ag Zwin
Then why do the cgi videos show it speeding up at impact and continuing through the building? The entire outside of that building were huge beams and a tin can went through it? Jesus,no wonder we are where we are now with so many blind sheep ready to go with the narrative. Do a little studying and then come back. building 7 fell why?
Study the building construction and a plane construction and come back with the same answer. Hell the frickin wings will fall off if landing hard enough. Tin can against massive steel, just doesn't pan out. A hundred other reasons if you break away from your porn long enough to learn something. Oh, and the vaccine works and is good for you! Dumba__
Study the building construction and a plane construction and come back with the same answer. Hell the frickin wings will fall off if landing hard enough. Tin can against massive steel, just doesn't pan out. A hundred other reasons if you break away from your porn long enough to learn something. Oh, and the vaccine works and is good for you! Dumba__
quote:
acceleration.
Well, I’d be willing to bet the acceleration of the planes at the time of impact was juuuuuust about zero.
Amateur engineers need to read up on heat and plastic deformation.
Posted on 9/12/22 at 8:15 pm to AtticusOSullivan
False flag incoming!!
Posted on 9/12/22 at 8:24 pm to Indefatigable
When I saw the first collapse, I knew it was a matter of time before the other went. It made sense that the tower that was hit lower was the first to collapse. More weight above it. At the time I really didn't think about them collapsing. I dont know why that didn't cross my mind, you just can't imagine that happening.
But to answer your question, I do think the higher impacted tower would've come down. I dont see NY influence from the other tower collapsing.
But to answer your question, I do think the higher impacted tower would've come down. I dont see NY influence from the other tower collapsing.
Posted on 9/12/22 at 8:27 pm to AtticusOSullivan
Saddest day in this nation’s history. Watched it happening while studying in a library in college. Crazy. RIP to all who lost their life.
Starting to understand the long term ramifications of that day the older I get.
9/11 completely changed humanity forever.
Starting to understand the long term ramifications of that day the older I get.
9/11 completely changed humanity forever.
Posted on 9/12/22 at 8:31 pm to Bayoutigre
quote:
if the beams at 70 th floor got weak the heating would be uneven,thus making the floors above topple over,not pancake into its own footprint, and fall at freefall speed
I don't know what the heat distribution was exactly but the evidence suggests it was enough to cause a cascade failure. That's what the evidence reasonably suggests.
Posted on 9/12/22 at 8:46 pm to APHA
quote:
Then why do the cgi videos show it speeding up at impact and continuing through the building? The entire outside of that building were huge beams and a tin can went through it? Jesus,no wonder we are where we are now with so many blind sheep ready to go with the narrative. Do a little studying and then come back. building 7 fell why?
Study the building construction and a plane construction and come back with the same answer. Hell the frickin wings will fall off if landing hard enough. Tin can against massive steel, just doesn't pan out. A hundred other reasons if you break away from your porn long enough to learn something. Oh, and the vaccine works and is good for you! Dumba__
You know it didn't hit a solid steel wall, there were windows interspaced between wooden beams very possible for parts of the plane to go through the building to the other side. Plus while the fuselage is aluminum many parts of the plane are not. Plus even something as thin as aluminum will still go through something when it's traveling at a couple hundred miles per hour.
Also when have wings fallen off a plane because it landed too hard?
Two hard landings I can think of the wings stayed attached, BA 38 landed short of the runway because of engine failure, but the wings stayed in tact. Asiana landed short of the runway I think bounced up and the wings stayed in tact. Airplanes may be light but they can take a beating.
This post was edited on 9/12/22 at 9:04 pm
Posted on 9/12/22 at 9:19 pm to APHA
Planes hir the buildings.
There was no way.to fake planes flying into them.
I'm not sure what the safety factor is on skyscraper structures. Maybe 2 or 3. For aircraft we have be at a minimum of 150% of the design load.
So we have to at least take loads 50% higher than what is designed for.
But let's say structures have to take 3x the actual loading.
Example:
Beam is capable of taking 300,000 psi
Actual load on beam is 100,000 psi. So a safety factor of 3.
Now add heat and reduce the allowable 50% and the capability of the beam is 150,000 psi.
Now factor in damage done to structures at impact. The plane is not a tin can. It weighs a lot, traveling fast and has a huge amount of kinetic energy. Yes the aluminum is weaker and lighter but it has a lot of energy and the steel beams absorbed all the energy. It doesn't absorb that amount of energy without being damaged.
Now interior structure at center of building is the backbone. If one beam is damaged, heated up more,.and is weakened more than the other vertical beams, it will begin to yield and give. The load that it can no longer hold is redistributed to surrounding structure. So building weight/load above this weak beam begins to find other load paths to more stable beams at the interior. So the interior beams are now taking extra load that the weak beam can't take. The total load at that floor tries to spread out and distribute load to all the beams.
Weakened beam can't take anymore load, surrounding vertical structure soaks up more and more load, until they all surpass the capability at that temperature and whatever damage they may have also. So you see the pancake effect.
When one beam finally gives load is instantly transferred to remains structure. It instantly surpasses its ability and they all let go together.
Load os like water and flows along load paths. When it comes to a part or path that begins to yield, it instantly finds other ways and paths to send the load.
There was no way.to fake planes flying into them.
I'm not sure what the safety factor is on skyscraper structures. Maybe 2 or 3. For aircraft we have be at a minimum of 150% of the design load.
So we have to at least take loads 50% higher than what is designed for.
But let's say structures have to take 3x the actual loading.
Example:
Beam is capable of taking 300,000 psi
Actual load on beam is 100,000 psi. So a safety factor of 3.
Now add heat and reduce the allowable 50% and the capability of the beam is 150,000 psi.
Now factor in damage done to structures at impact. The plane is not a tin can. It weighs a lot, traveling fast and has a huge amount of kinetic energy. Yes the aluminum is weaker and lighter but it has a lot of energy and the steel beams absorbed all the energy. It doesn't absorb that amount of energy without being damaged.
Now interior structure at center of building is the backbone. If one beam is damaged, heated up more,.and is weakened more than the other vertical beams, it will begin to yield and give. The load that it can no longer hold is redistributed to surrounding structure. So building weight/load above this weak beam begins to find other load paths to more stable beams at the interior. So the interior beams are now taking extra load that the weak beam can't take. The total load at that floor tries to spread out and distribute load to all the beams.
Weakened beam can't take anymore load, surrounding vertical structure soaks up more and more load, until they all surpass the capability at that temperature and whatever damage they may have also. So you see the pancake effect.
When one beam finally gives load is instantly transferred to remains structure. It instantly surpasses its ability and they all let go together.
Load os like water and flows along load paths. When it comes to a part or path that begins to yield, it instantly finds other ways and paths to send the load.
Posted on 9/12/22 at 9:19 pm to APHA
quote:
The entire outside of that building were huge beams and a tin can went through it?
I’ve seen pine needles, straw embedded in telephone poles from high winds of a tornado…deer completely destroying the front end of a suburban while the deer explodes into multiple pieces..a 767 traveling +450mph will certainly go through a skyscraper.
This post was edited on 9/12/22 at 9:28 pm
Posted on 9/12/22 at 9:26 pm to Taxing Authority
Taxing Authority, great example for non engineers. My explanation of load redistributing instantly when part of a structural yields, is summed up by your example.
Posted on 9/12/22 at 9:44 pm to Bayoutigre
Posted on 9/12/22 at 9:46 pm to AtticusOSullivan
gravity
Posted on 9/12/22 at 9:53 pm to catholictigerfan
So a plane traveling at 500+ mph should just splat against the side of the building like Wile E Coyote? 
Posted on 9/12/22 at 9:55 pm to Tyga Woods
quote:
So a plane traveling at 500+ mph should just splat against the side of the building like Wile E Coyote?
Lol that’s why he’s suggesting
Some are also suggesting that no airplane parts were found, so no planes!
It’s wild in here
Posted on 9/12/22 at 9:59 pm to jp4lsu
quote:
If one beam is damaged, heated up more,.and is weakened more than the other vertical beams, it will begin to yield and give. The load that it can no longer hold is redistributed to surrounding structure. So building weight/load above this weak beam begins to find other load paths to more stable beams at the interior. So the interior beams are now taking extra load that the weak beam can't take. The total load at that floor tries to spread out and distribute load to all the beams.
Weakened beam can't take anymore load, surrounding vertical structure soaks up more and more load, until they all surpass the capability at that temperature and whatever damage they may have also. So you see the pancake effect.
When one beam finally gives load is instantly transferred to remains structure. It instantly surpasses its ability and they all let go together.
Load os like water and flows along load paths. When it comes to a part or path that begins to yield, it instantly finds other ways and paths to send the load.
Thank you. I was hoping someone would spell it out. Well said.
Posted on 9/12/22 at 10:00 pm to jp4lsu
I wonder if it was a fellow engineer that downvoted my post above. Or somebody that thinks there were no planes.
Posted on 9/12/22 at 10:07 pm to jp4lsu
Posted on 9/12/22 at 10:07 pm to Tyga Woods
quote:And it should fall over in one piece from the bottom. Like when you chop down a tree.
So a plane traveling at 500+ mph should just splat against the side of the building like Wile E Coyote?
You know it was fake because no one yelled "TIMBER!!!".
Posted on 9/12/22 at 10:15 pm to Taxing Authority
To hell with math and physics
Page 15 of 16
Popular
Back to top
Follow TigerDroppings for LSU Football News