Basic Skyscraper Physics

[psikeyhackr]

I have kludged together a Python program that does a magical unsupported gravitational collapse. It is functionally the same as Fall of Physics but implemented via a different algorithm. The program loops computing the positions and velocities of the masses every 1/100th of a second.

http://www.thenakedscientists.com/fo...1656#msg251656

The differences came out less than 2%
Code:

Code: Select all

#   Fall of Physics
#
#   Case #1  2.5,  2.5,   2.5,    2.5  2.554 sec @ 43.82 ft/sec
#             0   16     23.85   29.93    
#   Program   0   15.84  23.79   29.6  2.57  sec @ 43.36 ft/sec
#
#   Case #2   1,   2,    3,      4     2.854 sec @ 38.66 ft/sec
#             0   10.67  16.87   21.70 
#   Program   0   10.56  16.8    21.6  2.87  sec @ 38.24 ft/sec
#
#   Case #3   4,   3,    2,      1     2.381 sec @ 50.37 ft/sec
#             0   18.29  29.05   38.91
#   Program   0   18.10  28.52   38.3  2.41  sec @ 49.856 ft/sec
#

So here is the program:

Code: Select all

#
#
# This program simulates a magical collapse of a skyscraper.
#
# It is magical in that the mass at each level is supported
#   by nothing!  Each mass is simply suspended in space
#   until struck from above.  At which point the conservation
#   of momentum determines the velocity of the combined
#   masses.
#
#   Up to line #69 with the f.close() the data for the
#   collapse is read from the argv[1] file.  It can have
#   any name since it is a command line argument.  This
#   program is started with:
#
#             python 911claps.py 911clpdt.csv
#
#   The data file has comma separated values with 5
#   parameters per line.  The first is the USE Flag which
#   tells the gravity function whether or not to ignore the
#   entire line.  If the mass has been absorbed in a
#   collision the USE Flag will be ZERO.  The next value is
#   the MOTION Flag.  This tells the gravity function
#   whether of not the mass is in motion.  If it is ONE then
#   the mass is accelerated for 0.01 second and velocity
#   and altitude are changed.  The 3rd value is Mass, the
#   4th is Velocity and the 5th is Altitude.
#
#   If the USE Flag is ONE and the MOTION Flag is ZERO then
#   the gravity function only reads and saves the altitude
#   for comparison to test for collisions.  This program
#   scans from the bottom up so the last altitude can be
#   compared to the new computed altitude of a Mass in
#   MOTION to do the collision test.
#
#   NOTE: There is a peculiarty in the program, most likely
#   because I haven't figured out something about Python.  The #   very first data line for the level at 12 feet is in the
#   program not the data file.  I was getting various errors
#   and just kludged it to get it done rather than spend more
#   time on Python syntax and error messages.
#

# Creates array of collapse data by reading file
# seems to work OK, 2010-05-07 12:14:20
import csv
import sys

# Haven't figured out the proper way to read in data so
# first data line for bottom of building is in program not the
# data file.

toweray = []
toweray.append(["1","0","2080.0","0.0","12.0"])

f = open(sys.argv[1], 'rt')
# create global variables
Time = 0.0
falling = 1
lastuslvl = 0
lastalt = 0.0
newalt = 0.0
velo = 0.0
dist = 0.0
# read data to fill array
reader = csv.reader(f)
rownum = 1
for row in reader:
    toweray.append([row[0],row[1],row[2],row[3],row[4]])
    rownum += 1
f.close()
print "\n\nTower Array is Loaded with",rownum,"Levels.\n\n"

inloop = 0
while inloop < 109&#58;
    toweray&#91;inloop&#93;&#91;0&#93;=int&#40;toweray&#91;inloop&#93;&#91;0&#93;&#41;
    toweray&#91;inloop&#93;&#91;1&#93;=int&#40;toweray&#91;inloop&#93;&#91;1&#93;&#41;
    toweray&#91;inloop&#93;&#91;2&#93;=float&#40;toweray&#91;inloop&#93;&#91;2&#93;&#41;
    toweray&#91;inloop&#93;&#91;3&#93;=float&#40;toweray&#91;inloop&#93;&#91;3&#93;&#41;
    toweray&#91;inloop&#93;&#91;4&#93;=float&#40;toweray&#91;inloop&#93;&#91;4&#93;&#41;
    inloop += 1
inloop = 0


def collide&#40;curntlvl&#41;&#58;
    global Time
    global falling
    global lastalt
    global lastuslvl
    global newalt
    print "Collision at",&#40;newalt + lastalt&#41;/2,"feet!!!"
    print "Mass @&#58;",toweray&#91;curntlvl&#93;&#91;4&#93;,"ft. hit Mass @&#58;",toweray&#91;lastuslvl&#93;&#91;4&#93;,"ft.",
    print "at&#58;",Time,"sec."
    print toweray&#91;curntlvl&#93;&#91;2&#93;,"tons traveling&#58;",
    print toweray&#91;curntlvl&#93;&#91;3&#93;,"ft/sec hit",
    print toweray&#91;lastuslvl&#93;&#91;2&#93;,"tons moving at&#58;",
    print toweray&#91;lastuslvl&#93;&#91;3&#93;,"ft/sec\n\n"
# Assimilate impacted Mass and turn off USE Flag
    newmass = toweray&#91;curntlvl&#93;&#91;2&#93; + toweray&#91;lastuslvl&#93;&#91;2&#93;
    toweray&#91;lastuslvl&#93;&#91;0&#93; = 0
# Apply Conservation of Momentum to compute new velocity
    newvel = &#40;toweray&#91;curntlvl&#93;&#91;2&#93; * toweray&#91;curntlvl&#93;&#91;3&#93; + toweray&#91;lastuslvl&#93;&#91;2&#93; * toweray&#91;lastuslvl&#93;&#91;3&#93;&#41;/newmass
    print "New mass is&#58;",newmass,"tons moving&#58;",newvel,
    print "ft/sec\n\n"
    toweray&#91;curntlvl&#93;&#91;2&#93; = newmass
    toweray&#91;curntlvl&#93;&#91;3&#93; = newvel
    lastalt = &#40;newalt + lastalt&#41;/2
    toweray&#91;curntlvl&#93;&#91;4&#93; = lastalt
    lastuslvl = curntlvl
    return

def gravity&#40;curntlvl&#41;&#58;
    global Time
    global falling
    global lastalt
    global lastuslvl
    global newalt
#    print "CL=",curntlvl,
    if int&#40;toweray&#91;curntlvl&#93;&#91;0&#93;&#41; == 0&#58; # If Use Flag Off return
        toweray&#91;curntlvl&#93;&#91;4&#93; = lastalt
        return
    elif int&#40;toweray&#91;curntlvl&#93;&#91;1&#93;&#41; == 0&#58; #If Motion Off get alt
        lastalt = toweray&#91;curntlvl&#93;&#91;4&#93;
        lastuslvl = curntlvl
        falling = 1
        return
    else&#58;
        falling = 1
        dist = 0.0016 + toweray&#91;curntlvl&#93;&#91;3&#93; * 0.01
        velo = 32 * 0.01 + toweray&#91;curntlvl&#93;&#91;3&#93;
        newalt = toweray&#91;curntlvl&#93;&#91;4&#93; - dist
        if newalt <= 0&#58;
            print "Mass&#58; #",curntlvl,"hit the ground.",
            print toweray&#91;curntlvl&#93;&#91;2&#93;,"tons at&#58;",
            print toweray&#91;curntlvl&#93;&#91;3&#93;,"ft/sec"
            toweray&#91;curntlvl&#93;&#91;0&#93; = 0
            lastuslvl = curntlvl
            return
        elif newalt <lastalt> 0&#58;
    falling = 0
    lastalt = 0
    inloop = 0
    Time += 0.01   
    if Time > 30&#58;  # End prog after 30 sec simulat
        break
    print "At the tone the Time will be&#58;", Time,"\n"
    while inloop < 109&#58;
        gravity&#40;inloop&#41;
        inloop += 1

Here is a data file with 10 ton increments all of the way down.

Code: Select all

1,0,2070.0,0.0,24.0
1,0,2060.0,0.0,36.0
1,0,2050.0,0.0,48.0
1,0,2040.0,0.0,60.0
1,0,2030.0,0.0,72.0
1,0,2020.0,0.0,84.0
1,0,2010.0,0.0,96.0
1,0,2000.0,0.0,108.0
1,0,1990.0,0.0,120.0
1,0,1980.0,0.0,132.0
1,0,1970.0,0.0,144.0
1,0,1960.0,0.0,156.0
1,0,1950.0,0.0,168.0
1,0,1940.0,0.0,180.0
1,0,1930.0,0.0,192.0
1,0,1920.0,0.0,204.0
1,0,1910.0,0.0,216.0
1,0,1900.0,0.0,228.0
1,0,1890.0,0.0,240.0
1,0,1880.0,0.0,252.0
1,0,1870.0,0.0,264.0
1,0,1860.0,0.0,276.0
1,0,1850.0,0.0,288.0
1,0,1840.0,0.0,300.0
1,0,1830.0,0.0,312.0
1,0,1820.0,0.0,324.0
1,0,1810.0,0.0,336.0
1,0,1800.0,0.0,348.0
1,0,1790.0,0.0,360.0
1,0,1780.0,0.0,372.0
1,0,1770.0,0.0,384.0
1,0,1760.0,0.0,396.0
1,0,1750.0,0.0,408.0
1,0,1740.0,0.0,420.0
1,0,1730.0,0.0,432.0
1,0,1720.0,0.0,444.0
1,0,1710.0,0.0,456.0
1,0,1700.0,0.0,468.0
1,0,1690.0,0.0,480.0
1,0,1680.0,0.0,492.0
1,0,1670.0,0.0,504.0
1,0,1660.0,0.0,516.0
1,0,1650.0,0.0,528.0
1,0,1640.0,0.0,540.0
1,0,1630.0,0.0,552.0
1,0,1620.0,0.0,564.0
1,0,1610.0,0.0,576.0
1,0,1600.0,0.0,588.0
1,0,1590.0,0.0,600.0
1,0,1580.0,0.0,612.0
1,0,1570.0,0.0,624.0
1,0,1560.0,0.0,636.0
1,0,1550.0,0.0,648.0
1,0,1540.0,0.0,660.0
1,0,1530.0,0.0,672.0
1,0,1520.0,0.0,684.0
1,0,1510.0,0.0,696.0
1,0,1500.0,0.0,708.0
1,0,1490.0,0.0,720.0
1,0,1480.0,0.0,732.0
1,0,1470.0,0.0,744.0
1,0,1460.0,0.0,756.0
1,0,1450.0,0.0,768.0
1,0,1440.0,0.0,780.0
1,0,1430.0,0.0,792.0
1,0,1420.0,0.0,804.0
1,0,1410.0,0.0,816.0
1,0,1400.0,0.0,828.0
1,0,1390.0,0.0,840.0
1,0,1380.0,0.0,852.0
1,0,1370.0,0.0,864.0
1,0,1360.0,0.0,876.0
1,0,1350.0,0.0,888.0
1,0,1340.0,0.0,900.0
1,0,1330.0,0.0,912.0
1,0,1320.0,0.0,924.0
1,0,1310.0,0.0,936.0
1,0,1300.0,0.0,948.0
1,0,1290.0,0.0,960.0
1,0,1280.0,0.0,972.0
1,0,1270.0,0.0,984.0
1,0,1260.0,0.0,996.0
1,0,1250.0,0.0,1008.0
1,0,1240.0,0.0,1020.0
1,0,1230.0,0.0,1032.0
1,0,1220.0,0.0,1044.0
1,0,1210.0,0.0,1056.0
1,0,1200.0,0.0,1068.0
1,0,1190.0,0.0,1080.0
1,0,1180.0,0.0,1092.0
1,0,1170.0,0.0,1104.0
1,0,1160.0,0.0,1116.0
1,0,1150.0,0.0,1128.0
1,0,1140.0,0.0,1140.0
1,1,1130.0,0.0,1152.0
1,1,1120.0,0.0,1164.0
1,1,1110.0,0.0,1176.0
1,1,1100.0,0.0,1188.0
1,1,1090.0,0.0,1200.0
1,1,1080.0,0.0,1212.0
1,1,1070.0,0.0,1224.0
1,1,1060.0,0.0,1236.0
1,1,1050.0,0.0,1248.0
1,1,1040.0,0.0,1260.0
1,1,1030.0,0.0,1272.0
1,1,1020.0,0.0,1284.0
1,1,1010.0,0.0,1296.0
1,1,1000.0,0.0,1308.0

This magical collapse only comes down in nearly the time of the real buildings because there is no support. Obviously in a REAL BUILDING the support has to be strong enough to hold all of the weight and the support itself has weight.

So we are being blathered to death to see that the obvious is never resolved. I have spreadsheet data from Urich and femr2 and they differ significantly so I will have to try them against my program.

But what calculation method can be used to simulate the structural resistance that doesn't just provide more junk to argue about?

This is discussed on another more technical website:

http://the911forum.freeforums.org/post10572.html#p10572

psik [3625]

[psikeyhackr]

Finally, collapse with sound and introduction by Ryan Mackey.

http://www.youtube.com/watch?v=ZT4BXIpdIdo

[4500]
psik

[psikeyhackr]

http://psikeyhackr.livejournal.com/1276.html

http://psikeyhackr.livejournal.com/1500.html

[5920]
psik

[psikeyhackr]

This is amazing. With all of the talk about the design of the WTC towers I don't recall seeing discussions of the column density compared to NORMAL skyscrapers. Normal skyscraper like the Empire State Building have columns in a rectangular grid with columns spaced 30 feet apart, center to center. So there would be 24 columns in an area 90 by 150 feet which is larger than a WTC core.

(47÷(85×135))÷(24÷(90×150)) = 2.304

So with 47 columns the core had 2.3 times the column density of a normal skyscraper.

But there were 59 perimeter columns on each side of the building.

((47+4*59)÷(208×208))÷(64÷(210×210)) = 4.507

So a normal skyscraper would have 8 columns on a 210 foot side and thus only have 64 columns in the building. So above the 9th floor the WTC had 4.5 times the usual number of columns per square foot of floor space.

But we are supposed to believe these buildings could collapse whereas normal skyscrapers would not.

Curious how no structural engineers have been talking about the column density in all of this time.

[9300]
psik

[psikeyhackr]

it recently occurred to me how to combine computer precision with physical modelling that would probably prevent cheating via computer lies.

3D printing!

Use a 3D printer to produce each level of the north tower. The thickness of columns could be varied to the level of precision of the printer. Each level could be made as strong or as weak as desired. Empty spaces could be left to insert metal slugs or ball bearings to control the weight of each level. And the printing process would mean it would not be to difficult to do multiple tests. They could be repeated all over the world.

So how big are 3D printers to scale 208 ft by 208 ft?

If the printer could make and object 2 feet by 2 feet then each level would be 1.5 inches tall. The floors would be pretty thin.

It would still be an expensive project but it would make it possible for the core and perimeter to maintain a consistent pattern without tremendous amounts of construction by hand which could not be as consistent.

[psikeyhackr]

These are how the columns would be arranged in the WTC if it had been the usual grid design.

Code: Select all

. . . . . . . .
. . . . . . . .
. . . . . . . .
. . . . . . . .
. . . . . . . .
. . . . . . . .
. . . . . . . .
. . . . . . . .

But this is what that graphic shows:

Code: Select all

  . . . . . . . , , , ,  
. . . . . . . .*,*,*,*,*,
. . . . . . . .*,*,*,*,*,
. . . . . . . .*,*,*,*,*,
. . . . . . . .*,*,*,*,*,
. . . . . . . .*,*,*,*,*,
. . . . . . . .*,*,*,*,*,
. . . . . . . .*.*,*,*,*,
,*,*,*,*,*,*,*,*,*,*,*,*,
,*,*,*,*,*,*,*,*,*,*,*,*,
,*,*,*,*,*,*,*,*,*,*,*,*,
,*,*,*,*,*,*,*,*,*,*,*,*,
  ,*,*,*,*,*,*,*,*,*,*,  

The commas are the additional columns and the * is the additional space. So it is either a building with three times the area of the WTC or it has columns only 17 feet apart.

This animation has 13 columns on the side also, at 2:06.

https://www.youtube.com/watch?v=wRf5pCj2XS8

The animation moves the columns from a grid arrangement to the WTC arrangement but it only puts 31 columns on each side of the perimeter at 2:14. It has 45 columns in the core which is close to the correct number.

13 times 13 would be 169. So 4 times 31 + 45 is 169. So that animation has the same number of columns in both versions but later in the video they specify the correct number of columns on each side of the perimeter and the total for the real WTC. But they never say that a normal grid skyscraper the size of the WTC would have columns 30 feet apart and so would only have 64 columns, so the animation is misleading about other skyscrapers. Since the animation just moves columns to the WTC arrangement it is using the same floor area for both. So the columns could not be 30 feet apart, only 17 which it not the usual arrangement.

The Empire State Building is still 83 years old and they didn't have electronic computers to design it. So engineers are just pretending this structural engineering crap is more difficult to comprehend than it actually is. They would look pretty stupid after TWELVE YEARS if they admitted collapse was impossible. So they are stuck with having to pretend the problem is difficult.

Engineers can't even talk about the distributions of steel and concrete down the towers after TWELVE YEARS. That would have to be similar in both designs regardless of the horizontal arrangement of the columns.

https://www.youtube.com/watch?v=QYJ1IePcgVU

https://www.youtube.com/watch?v=pBQSdnCkiPE

[13022]
psik