a Daiwa House Industry Co., Ltd., Kita, Osaka, Japan b Nihon University, Chiyoda, Tokyo, Japan
c Building Research Institute, Tsukuba, Ibaraki, Japan d University of Tokyo, Kashiwa, Chiba, Japan
General Instructions
919
THEORETICAL TORNADO MODEL
Statistical Information of Tornado-induced Damage in Japan and Assumptions for Modeling
Time History and Occurrence Probability of Simulated Tornado Model
0
30
60
90
120
150
180
-90
-60
-30
0
30
60
90
0 5 10 15 20 25 30
t(s)
V(m/s) )
b) center0
30
60
90
120
150
180
-60
-30
0
30
60
90
120
0 5 10 15 20 25 30
wind speed (m/s)-axis(m/s)-axis(m/s)
directiont(s)
V(m/s) )
a) right side
920
Tornado Generator Facilities
1
10
100
1000
10
15
20
25
30
35
40 60 80 100 120 140 160
USA;Moving speed
JPN;Moving speed
USA;Core radius
JPN;Core radius
V(m/s)
V(m/s) (m)
921
Characteristics of Wind Speed and Direction Changes of Tornado Winds
0.0
1.0
2.0
3.0
4.0
5.0
-150 -120 -90 -60 -30 0 30 60 90 120 150
V(m/s)
X(mm)Z-Z
diameter=200mm
radius=100mm
center
922
z
xy
fan(1, ; )fan(2, ; )fan(3, ; )fan(4, ; )fan(5, ; )fan(6, ; )
0
20
40
60
80
100
120
140
160
180
0
1
2
3
4
5
6
-1.0 -0.8 -0.6 -0.4 -0.2 0.0 0.2 0.4 0.6 0.8 1.0
wind velocity(SA)wind velocity(R)wind velocitydirection(SA)directiondirection(R)
V(m/s)
)
(m)
-20
0
20
40
60
80
100
120
140
160
180
200
0
1
2
3
4
5
6
-1.0 -0.8 -0.6 -0.4 -0.2 0.0 0.2 0.4 0.6 0.8 1.0
V(m/s) )
(m)
0
20
40
60
80
100
120
140
160
180
0
1
2
3
4
5
6
-1.0 -0.8 -0.6 -0.4 -0.2 0.0 0.2 0.4 0.6 0.8 1.0
V(m/s))
(m)
-20020406080100120140160180200
0
1
2
3
4
5
6
-1.0 -0.8 -0.6 -0.4 -0.2 0.0 0.2 0.4 0.6 0.8 1.0
V(m/s) )
(m)
923
-8.0 -6.0 -4.0 -2.0 0.0 2.0 4.0 6.0
5 10 15 20
fan(1, ; ) fan(2, ; ) fan(3, ; )fan(4, ; ) fan(5, ; ) fan(6, ; )
t(s)
v'
-8.0 -6.0 -4.0 -2.0 0.0 2.0 4.0 6.0
5 10 15 20
t(s)
v'
Simulation of Non-stationary Wind Flow based on Tornado Characteristics
x=600
y=300
z=300
UR(t),PS(t)measure point
fan(1, ; )
fan(2, ; )
fan(3, ; )
fan(4, ; )
fan(5, ; )
fan(6, ; )
wind line
model
-20 -15 -10 -5 0 5 10 15 20
0.0 0.5 1.0 1.5 2.0 2.5 3.0
5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
wind velocitydirection
V(m/s) D( )
t(s)-20 -15 -10 -5 0 5 10 15 20
0.0 0.5 1.0 1.5 2.0 2.5 3.0
5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
V(m/s) D( )
t(s)
924
Distributions of Wind Speed and Direction
Wind Pressure Measurements on Square Prism Model
tp tps tU R
tU
tptptC
R
sp
925
200
250
300
350
400
500 550 600 650 700 750
z(mm)
x(mm)
1 2 3 4 5
11 12 13 14 15
21 22 23 24 25
6 7 8 9 10
16 17 18 19 20
wind measure point
model place
wind
-1.5
-1
-0.5
0
0.5
1
1.5
2
1 2 3 4 5 6 7 8 9 10 11 12
-10s)
-20s)
Cp
( )
-2.0
-1.5
-1.0
-0.5
0.0
0.5
1.0
5 10 15 20 25
point7 point8
point9 point10
point11 point12
Cp
t(s)
926
Calculation of Wind Force Coefficients
20within1sec
-2.0
-1.5
-1.0
-0.5
0.0
0.5
1.0
1.5
2.0
0 1 2 3 4 5 6 7
ch.1 ch.4 ch.5
ch.6 ch.7 ch.9 t(s)
0 45 90 11020 70
t(s)
Cp
-0.20
-0.10
0.00
0.10
0.20
-1.0
-0.5
0.0
0.5
1.0
1.5
2.0
2.5
3.0
5 10 15 20 25
CFx
CFy
CM
t(s)
-0.20
-0.10
0.00
0.10
0.20
-1.0
-0.5
0.0
0.5
1.0
1.5
2.0
2.5
3.0
5 10 15 20 25
CFx
CFy
CM
t(s)
927