Environmental Engineering Reference
In-Depth Information
Symbol
Reference
DIN 1055-4
annex C
DIBt
guideline
Aerodynamic transfer
function (width)
R
b
(C.16)
0.871
h
b
(C.16)
0.21
R
x
Squared resonance response
component of gust response
(C.11)
1.879
2.227
Coefficient
S
(C.8)
1.644
n
E,0
[s
1
]
Frequency of gust
response - quasi-static
(C.7)
0.109
n
E
[s
1
]
Expected value of
frequency of gust response
(C.6)
0.258
0.258
Peak factor
g
(C.5)
3.364
3.364
Gust response factor
G
(C.4)
2.448
2.542
Dynamic pressures taking into account the gust response
a) Evaluation according to DIN 1055-4 [12]:
q
j
¼
G
q
m
;
j
where
q
m,j
average dynamic pressure in segment j (q
m
(z
j
))
G
gust response factor to DIN 1055-4 [12]:
q
Q
0
þ
R
x
G
¼
1
þ
2
g
I
v
z
ðÞ
b) Simplified calculation to DIN 1056 [13]:
q
j
¼ w
B
q
B
;
j
where
q
B,j
dynamic pressure taking into account the gust response in segment j (q
B
(z
j
))
w
B
gust response factor to DIN 1056 [13]
1)
:
0019
T
1
Þd
0
:
63
w
B
¼
Max
½
:
ð
1
:
05
h
=
1000
;
1
:
0
Þ
1
þð
0
:
042
T
1
0
:
with logarithmic damping decrement
d ¼
0.10 (reinforced concrete in cracked state or at the
ultimate limit state)
1)
Wind turbine example (5.2):
w
B
¼
1.0
[1
þ
(0.042
3.46
0.0019
3.46
2
)/0.10
0.63
]
¼
1.523 (
<
G
¼
2.448).
