Transcript Friction Damper with Coned Disc Springs

Friction Damper with Coned disc springs
August, 2001
Obayashi Corporation
Laminated Rubber Bearing
Lead plug
Lead Rubber Bearing
Natural Rubber Bearing
High Damping Rubber Bearing
Damper Selection Line-up
Steel damper
Lead damper
Oil damper
Friction damper with
Coned disc springs
Feature of Dampers
① Steel damper
③ Oil damper
Δ Energy Absorption
Δ Stroke limit
Δ Directional operation
X Load Support
○ Energy Absorption
Δ Stroke limit
X Directional operation (one direction)
X Load Support
② Lead damper
④ Friction damper with
Δ Energy Absorption
Δ Stroke limit
Δ Directional operation
X Load Support
Coned disc springs
○ Energy Absorption
Δ Stroke limit
○ Directional operation
○ Load Support
Outline of Coned Disc Spring
h=14.7
2b=190
t=11.0
2a=420
Unit/mm
Vertical Load-deflection Curves
of Coned disc spring
20
Vertical load (tonf)
[III]
15
[ II ]
10
Test
Analysis
FEM
5
0
[I]
0
10
Vertical Displacement (mm)
Sectional plan of Coned disc spring
[I]
5
[ II ]
15
[III]
Combination of Coned disc springs
Two columns of single disc
40
40
30
30
[tonf]
[tonf]
Single Disc
20
10
10
0
0
0
10
20
30
40
[mm]
Double Discs
0
40
40
30
30
20
10
0
0
10
20
30
40
[mm]
10
20
30
Two columns of double discs
[tonf]
[tonf]
20
40
[mm]
20
10
0
0
10
20
30
40
[mm]
Feature of Coned disc spring
・Get big Resilient force by compact sized coned disc spring
・Linear or nonlinear load-defection curve can be gained by coned
disc spring
・Get many kind of load-deflection curve by combination coned
disc springs
・Use semi-permanently under allowable stress
Outline of Friction Damper
with Coned disc springs
Height of Coned disc springs/ 240
460
560
Inner Guide
Coned disc springs
Sliding material
Stainless Steel Plate
400
Unit / mm
Principle of the Friction damper
of Coned disc Springs
Friction force
Movement
W : Weight
F : Friction force
Friction force
F=W  : Frictional coefficient
Superstructure
Resilient
force N
Rubber
bearing
Foundation
Horizontal Friction Force F
Stainless steel plate
Horizontal friction force F is occurred when
pressing down the sliding plate(UHMWP) by
multiple coned disc springs resilient force N
against stainless steel plate
Resilient force N
Compress the multiple
coned disc springs to
occur resilient force
Coned
disc
springs
Sliding plate
(UHMWP)
F  N  :Frictional coefficient
Independence of the height changes of rubber bearing
In the state of the rubber bearing
height becomes short by low
temperature and creep
In the state of the rubber bearing
height becomes high by high
temperature
Up-lift : b
Go-down : a
Resilient
force N2
Resilient
Initial heightResilient
force n2
force n1 force N1
Linear spring Nonlinear coned
Linear spring Nonlinear coned
disc springs
disc springs
[Linear spring]
[Nonlinear coned disc springs]
Initial heightResilient
n1
Resilient
force
Resilient
force
N1
N2
n2
Vertical
displacement
b a
Vertical
displacement
b a
Resilient variation force of
nonlinear coned disc springs
is smaller than that of linear
spring by change of rubber
bearing height, and variation
of friction force is so.
For supporting function of the friction damper
with coned disc springs
Normal time
Emergent excessive earthquake
Weight 100%
Weight 100%
Superstructure
Support 75%
Foundation
Superstructure
Support 25%
Rubber bearing
Stainless steel plate
In normal time, most of superstructure
weight is supported by rubber bearing
(ex. 75%)
Support 10%
Foundation
Support 90%
In emergent excessive earthquake, rubber bearing
will have large horizontal displacement and
cannot support superstructure, then the friction
damper takes support it ins
[For EQ Load]
0.4
0.2
0
-0.2
-0.4
-40
Frictional coefficient
[For Wind Load]
Frictional coefficient
Horizontal hysteresis loops of the Friction
damper with coned disc springs
-30
-20
-10
0
10
20
Horizontal displacement (mm)
30
40
-100
-50
0
50
100
Horizontal displacement (mm)
150
200
0.4
0.2
0
-0.2
-0.4
-200 -150
Multi Function for the friction damper
with coned disc springs
1. Restrain the movement by strong wind
(Improvement for dwelling ability)
2. Stable damper for earthquake
(Damper function)
3. Support load function
(Safety device function)
New Base Isolation Building
Oil Damper
The new base-isolation building in Nagoya
Friction damper with
coned disc springs
The new base-isolation building
in Nagoya
Oil damper
Friction damper with
coned disc springs
Oil damper
Friction damper with
coned disc springs
Rubber bearing
Rubber bearing
Elevation
Plan
Inner Guide
Vertical force (tonf)
Feature of the friction damper
with coned disc springs
40
35
30
25
20
15
10
5
Available zone
0
0
10
20 30 40 50 60 70
Vertical displacement (mm)
80
Multiple coned
disc springs
Stainless steel plate
Sliding Plate
Outline of the friction damper
with coned disc springs
Friction force (tonf)
Vertical load-deflection curves
12
8
4
0
-4
-8
-12
-200 -150 -100 -50 0
50 100 150 200
Horizontal displacement (mm)
Horizontal hysteresis loops
Feature of the friction damper
with coned disc springs
・Adjust the friction force by the combination coned disc
springs of the friction damper
・To operate in all direction, and stroke is limited by the
area of stainless steel plate
・Friction force is stable constant
・Friction damper can support the load
・Easy to set the friction damper with coned disc springs