Passive, Semi-Active and Active Vibration Control Systems for ...
Passive, Semi-Active and Active Vibration Control Systems for ...
Passive, Semi-Active and Active Vibration Control Systems for ...
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<strong>Passive</strong>, <strong>Semi</strong>-<strong>Active</strong> <strong>and</strong> <strong>Active</strong><br />
<strong>Vibration</strong> <strong>Control</strong> <strong>Systems</strong> <strong>for</strong> Offshore<br />
Plat<strong>for</strong>m Steel Jacket Structures<br />
OU Jinping<br />
WU Bin XIAO Yiqing DUAN Zhongdong et al<br />
Harbin Institute of Technology<br />
P.R. China
About HIT<br />
• Undergraduates: 21,000<br />
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in which faculties: 2,700<br />
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Aerospace<br />
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Mechanical engineering<br />
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Civil engineering, Architecture
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1/3 from Aerospace Bureau<br />
1/3 from government agencies<br />
1/3 from industry companies<br />
• The total sale of Hi-Tech products<br />
of the Science Park in 2001: 2110 millions<br />
• HIT is one of top 9 universities getting<br />
key financial support from the government
Background
�More than 5000 steel offshore<br />
structures in the world<br />
100 in China<br />
�Main dynamic excitations:<br />
wind, wave, ice <strong>and</strong> earthquake<br />
�<strong>Vibration</strong> amplitude reduced 15%<br />
the life of structure enhance double
�mail control loads in Bohai Ocean of<br />
China<br />
Ice <strong>for</strong>ce <strong>and</strong> Earthquake<br />
Seismic <strong>for</strong>tified intensity:8 degree<br />
�2 plat<strong>for</strong>ms collapsed by ice<br />
in China (1969,1977)<br />
2 collapsed in USA (1964)
•It is urgent to have an effective scheme to<br />
control ice-induced <strong>and</strong> earthquake-induced<br />
vibration of offshore structures<br />
<strong>for</strong> ocean oil development<br />
Some effective control schemes<br />
<strong>for</strong> buildings may not work <strong>for</strong><br />
offshore structures since<br />
underwater <strong>and</strong> corrosion
I. Damping brace control<br />
systems(DBS)<br />
II. <strong>Passive</strong> <strong>and</strong> semi-active<br />
damping isolation systems(DIS)<br />
III. AMD control systems
JZ20-2MUQ<br />
1:10 Model<br />
Placement of<br />
Damper<br />
Õ³ ÖÍ º ÄÄÜ<br />
Æ÷¼° б³ Å
• <strong>Passive</strong> <strong>Vibration</strong> <strong>Control</strong><br />
with Viscous or Visoelastic Dampers
1.1 Design <strong>and</strong> Tests of Viscous Dampers<br />
1) Configurations of viscous dampers<br />
(a) With a gap<br />
(b) With holes
2) Tests of scale dampers with a gap<br />
i) Damping media:<br />
¼ôÓ¦Á¦(Pa)<br />
Fluid with<br />
power law<br />
20<br />
16<br />
12<br />
8<br />
4<br />
0<br />
0 1 2 3<br />
¼ôÓ¦±äËÙÂÊ(1/s)<br />
Silicon oil 7000<br />
τ = kγ&<br />
m<br />
Tested curves of the media<br />
under low shear velocity
Configuration Parameters of dampers<br />
Damper 1<br />
D = 40 mm 0 39.<br />
2 = D mm<br />
l = 39 mm d = 20 mm<br />
Damper 2<br />
D = 80 mm 0 79 = D mm<br />
l = 40 mm d = 45 mm
×èÄáÁ¦(KN)<br />
6<br />
3<br />
0<br />
-3<br />
-6<br />
Tested damping <strong>for</strong>ces<br />
•Damper 1<br />
-6 -4 -2 0 2 4 6<br />
λÒÆ(mm)<br />
×èÄáÁ¦(KN)<br />
9<br />
6<br />
3<br />
0<br />
-3<br />
-6<br />
-9<br />
-6 -4 -2 0 2 4 6<br />
λÒÆ(mm)<br />
Case a3 Case a4
×èÄáÁ¦(KN)<br />
12<br />
8<br />
4<br />
0<br />
-4<br />
-8<br />
•Damper 2<br />
-12<br />
-6 -4 -2 0 2 4 6<br />
λÒÆ(mm)<br />
×èÄáÁ¦(KN)<br />
-12 -8 -4 0 4 8 12<br />
Case b3 Case b4<br />
6<br />
3<br />
0<br />
-3<br />
-6<br />
λÒÆ(mm)
2) Damping<br />
media:<br />
Bingham<br />
fluid<br />
Configuration parameters of damper<br />
D =100 mm<br />
d =40 mm<br />
D0 =96 mm<br />
l =40 mm<br />
h =2 mm<br />
Bingham fluid<br />
τ τ = η & γ<br />
− 0<br />
p
×èÄáÁ¦(kN)<br />
×èÄáÁ¦(kN)<br />
Tested damping <strong>for</strong>ce<br />
6<br />
4<br />
2<br />
0<br />
-2<br />
-4<br />
-6<br />
-10 -5 0 5 10<br />
λÒÆ(mm)<br />
f=0.5Hz, A=10mm<br />
6<br />
4<br />
2<br />
0<br />
-2<br />
-4<br />
-6<br />
-10 -5 0 5 10<br />
λÒÆ(mm)<br />
f=1Hz, A=10mm<br />
×èÄáÁ¦(kN)<br />
×èÄáÁ¦(kN)<br />
6<br />
4<br />
2<br />
0<br />
-2<br />
-4<br />
-6<br />
-6 -4 -2 0 2 4 6<br />
6<br />
4<br />
2<br />
0<br />
-2<br />
-4<br />
-6<br />
λÒÆ(mm)<br />
f=1Hz, A=5mm<br />
-6 -4 -2 0 2 4 6<br />
λÒÆ(mm)<br />
f=2Hz, A=5mm
3) Tests of full scale damper with Bingham fluid<br />
The configuration of damper<br />
Configuration parameters of damper<br />
D =200 mm<br />
d =100 mm<br />
D0 =196 mm<br />
l =200 mm<br />
h =2 mm
×èÄáÁ¦(kN)<br />
400<br />
300<br />
200<br />
100<br />
0<br />
-100<br />
-200<br />
-300<br />
-400<br />
Tested results f=1 Hz<br />
-9 -6 -3 0 3 6 9<br />
λÒÆ(mm)<br />
A=8.71mm<br />
×èÄáÁ¦(kN)<br />
400<br />
300<br />
200<br />
100<br />
0<br />
-100<br />
-200<br />
-300<br />
-400<br />
-12 -8 -4 0 4 8 12<br />
λÒÆ(mm)<br />
A=12.80mm
1.3 The Tested Responses of Offshore Structures<br />
with / without Viscous Dampers El Centro<br />
Maximum Displacement<br />
<strong>and</strong> Maximum Acceleration<br />
Reduction ratio: 42%
2. Smart <strong>Vibration</strong> <strong>Control</strong><br />
with MR Dampers
Type A (carrier fluid’s viscosity is 70 centistoke)<br />
Yi el d st r ess£¨ kPa£©<br />
40<br />
35<br />
30<br />
25<br />
20<br />
15<br />
10<br />
5<br />
0<br />
1. Magnetorheological Fluid<br />
<strong>and</strong> Smart Damper<br />
1) Properties of MR fluid<br />
0 0.1 0.2 0.3 0.4<br />
Magnet i c i nduct i on£¨ T£©
Type B (carrier fluid’s viscosity is 2000<br />
centistoke)<br />
Yi el d st r ess£¨ kPa£©<br />
40<br />
35<br />
30<br />
25<br />
20<br />
15<br />
10<br />
5<br />
0<br />
0 0.1 0.2 0.3 0.4<br />
Magnet i c i nduct i on£¨ T£©
40<br />
35<br />
30<br />
25<br />
20<br />
15<br />
10<br />
5<br />
0<br />
0 0. 1 0. 2 0. 3 0. 4<br />
Yi el d st r ess£¨ kPa£© •Property comparison of MR fluid<br />
Magnet i c i nduct i on£¨ T£©<br />
Type A ( OU,et al, 1998) Lord Ltd. (1995)
2) MR damper<br />
Table 4 Parameters <strong>for</strong> MR damper<br />
h(mm) D(mm) d(mm) L(mm)<br />
2 100 40 40<br />
The schematic
3) Damping properties<br />
a Amplitude=1.5cm<br />
frequency=0.25Hz<br />
b Amplitude=1.5cm<br />
frequency=0.5Hz
a Amplitude=1.5cm<br />
frequency=0.25Hz<br />
b Amplitude=1.5cm<br />
frequency=0.5Hz
2. Numerical Analysis of Smart <strong>Vibration</strong><br />
<strong>Control</strong> of JZ20-2MUQ Plat<strong>for</strong>m Structures<br />
1) <strong>Passive</strong>-Off <strong>and</strong> <strong>Passive</strong>-On<br />
<strong>Passive</strong> -Off<br />
Under ice <strong>for</strong>ce of 1 year return Under El Centro earthquake (190 gal)
2) Fuzzy <strong>Control</strong> Rules <strong>for</strong> Offshore Structure<br />
NB NM NS ZE PS PM PB<br />
NB PB PB NS NM NB NB NB<br />
NM PB PB ZE NS NM NB NB<br />
NS PB PB PS NS NS NB NB<br />
ZE PB PB PS ZE NS NB NB<br />
PS PB PB PS PS NS NB NB<br />
PM PB PB PM PS ZE NB NB<br />
PB PB PB PB PM PS NB NB<br />
⎧Fmin<br />
F ⋅ FMR<br />
≤ 0 or F < Fmin<br />
⎪<br />
Fcoul = ⎨Fmax<br />
F ⋅ FMR<br />
> 0 <strong>and</strong> F > Fmax<br />
⎪<br />
⎩F<br />
ÆäËûÇé¿ö
3) Numerical results<br />
�El-Centro earthquake
• Damping Force under Fuzzy <strong>Control</strong> Rules<br />
Damping <strong>for</strong>ce versus displacement Damping <strong>for</strong>ce versus velocity
• Displacement response under Ice Force<br />
Under the crushed ice <strong>for</strong>ce of 1 year return
Under the bended ice <strong>for</strong>ce of 1 year return
�<strong>Control</strong> effectiveness<br />
• Under earthquke<br />
– 23 30<br />
• Under ice <strong>for</strong>ce<br />
– 33 47 <strong>for</strong> light ice<br />
– 30 50 <strong>for</strong> heavy ice
3. Shaking Table Tests of Smart <strong>Vibration</strong><br />
<strong>Control</strong> of Scale Model Plat<strong>for</strong>m<br />
Structures<br />
<strong>Control</strong> strategy<br />
–<strong>Passive</strong>Off –<strong>Passive</strong>On – <strong>Semi</strong>-active fuzzy control
•<strong>Control</strong> rules<br />
¿ØÖÆÐźÅ(V)<br />
4<br />
2<br />
0<br />
15<br />
10<br />
ËÙÈ<br />
5<br />
0<br />
0<br />
5<br />
λ Ò Æ<br />
10<br />
15
Tested Results<br />
� <strong>Passive</strong> Off <strong>Passive</strong> On <strong>Semi</strong>-active<br />
fuzzy control have the same results:<br />
0.6 - 37
The reason:<br />
Damping <strong>for</strong>ce versus displacement <strong>and</strong><br />
velocity<br />
×èÄáÁ¦£ ¨ Ö£ ©<br />
1.5<br />
1<br />
0.5<br />
¼ÓÔØËÙ È 1cm/s<br />
0 A<br />
2 A<br />
0<br />
0 1 2 3 4 5<br />
Î »ÒÆ£¨cm£ ©
II. <strong>Passive</strong> <strong>and</strong> semi-active<br />
damping isolation systems(DIS)
<strong>Passive</strong> <strong>and</strong> semi-active damping<br />
isolation systems(DIS)<br />
¸ô Õð×èÄá Æ÷
Damping isolation mechanism<br />
� Traditional isolation increase or reduce the<br />
fundamental period <strong>and</strong> avoid the predominant<br />
period of excitation, <strong>and</strong> then suppress the<br />
vibration of structure.<br />
� Damping isolation lay a flexible layer to make<br />
the dampers dissipate vibration energy as much<br />
as possible, <strong>and</strong> then suppress the vibration of<br />
structure
� The local damping coefficient can be<br />
transferred into the damping ratio of<br />
whole structure, then suppress the<br />
vibration of structure<br />
m2<br />
m1<br />
MX&& + CX&+ KX = F() t<br />
m >><br />
2<br />
m<br />
⎡ c1 +c2 -c2 ⎢<br />
⎣ -c2 c2 1<br />
⎤<br />
⎥<br />
⎦<br />
c ξ<br />
2
Relationship of damping coefficient c 2 in isolation<br />
layer <strong>and</strong> damping ratio ξ 1 of structure<br />
ξ 1<br />
0. 5<br />
0. 4<br />
0. 3<br />
0. 2<br />
0. 1<br />
k 2 =0. 3k 1<br />
k 2 =0. 5k 1<br />
0. 0<br />
1000 2000 3000 4000 5000 6000 7000 8000 9000 10000<br />
c 2 (kN s/m)
• <strong>Control</strong> Effectiveness with viscous dampers<br />
(Numerical results)<br />
• Under ice <strong>for</strong>ce<br />
Relative displacement of isolated layer: 30mm<br />
Reduction ratio:<br />
Displacement 30%<br />
Acceleration 50%<br />
2. Under earthquake (190gal)<br />
Relative displacement of isolated layer: 50mm<br />
Reduction ratio:<br />
Displacement 35%<br />
Acceleration 30%
•<strong>Control</strong> Effectiveness with MR dampers<br />
(Numerical results)<br />
Under Taft earthquake (190 gal)<br />
Case Relative<br />
displacement<br />
of damping<br />
layer (cm)<br />
Without<br />
control<br />
Max. displ. of<br />
jacket<br />
structure (cm)<br />
Max. accel. of<br />
jacket<br />
structure<br />
(cm/s 2 )<br />
6.63 198.90<br />
<strong>Passive</strong> off 3.32 1.11 64.20<br />
<strong>Passive</strong> on 1.72 1.32 129.98<br />
<strong>Semi</strong>-active 1.68 1.27 105.28
III. AMD control systems
3.1 Numerical Analysis<br />
• Main Parameters of AMD <strong>Systems</strong><br />
<strong>for</strong> the <strong>Vibration</strong> <strong>Control</strong> of JZ20-2MUQ<br />
Plat<strong>for</strong>m In Baihai Ocean<br />
Mass: 100 t mass ratio: 4%<br />
Maximum control <strong>for</strong>ce: 120 t<br />
Maximum displacement of the mass :0.8 m
EL+39.750<br />
EL+16.5000<br />
EL-23.500<br />
AMD Without<br />
control<br />
� Under earthquake<br />
– Elcentro with Max<br />
Acce. 220gal<br />
� <strong>Control</strong> effectiveness<br />
– Disp. 46.8%<br />
– Acce. 31.4%
EL+39.750<br />
EL+16.5000<br />
EL-23.500<br />
AMD Without<br />
control<br />
• Under ice <strong>for</strong>ce<br />
– Crushed ice <strong>for</strong>ce<br />
40cm<br />
• <strong>Control</strong><br />
effectiveness<br />
– Disp. 33%<br />
–Acce. 44%
3.2 Tests of 1:10 Model with AMD<br />
<strong>Control</strong> algorithm<br />
� LQG with acceleration feedback<br />
� <strong>Control</strong>ler<br />
� Single input acceleration of deck<br />
� Single output voltage of actuator
Acceleration gal<br />
Displacement mm<br />
Under Taft Earthquake (190 gal)<br />
5<br />
0<br />
-5<br />
0 2 4 6 8 10 12<br />
500<br />
0<br />
-500<br />
0 2 4 6 8 10 12<br />
(sec)
•<strong>Control</strong> effectiveness<br />
(Tested results)<br />
� Input earthquake<br />
� El Centro 300gal Taft 250gal<br />
Tianjing 120gal<br />
� Reduction ratio of disp. 17 47 45<br />
� Reduction ratio of accel. -6 52 38<br />
� Actuator<br />
� Max disp. 13.8mm 6.1mm 7.9mm<br />
� Max. <strong>for</strong>ce 1.93 kN 1.20kN 1.22kN
Conclusions<br />
Recommended control schemes<br />
<strong>for</strong> offshore structures:<br />
• <strong>Passive</strong> <strong>and</strong> semi-active damping<br />
isolation systems(DIS)<br />
•AMD control systems