Novel Super-high Damping Natural Rubber Woothichai Thaijaroen Pram - - PowerPoint PPT Presentation

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Novel Super-high Damping Natural Rubber Woothichai Thaijaroen Pram - - PowerPoint PPT Presentation

Jun 29, 2023 740 likes •950 views

Novel Super-high Damping Natural Rubber Woothichai Thaijaroen Pram Yodjun Weenusarin Intiya MTEC - Mahidol 1 Rubber : Damping F force W displacement F F bigger loop : higher damping : higher energy dissipation 2 Applications bridge

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Novel Super-high Damping Natural Rubber

Woothichai Thaijaroen Pram Yodjun Weenusarin Intiya

MTEC - Mahidol

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Rubber : Damping

force displacement

W F F F

bigger loop : higher damping : higher energy dissipation

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SLIDE 3

Applications

seismic bearing bridge bearing dock fender suspension bush

Damping ratio ≤ 10% : normal damping 10% < Damping ratio ≤ 15% : high damping Damping ratio > 15% : super-high damping

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SLIDE 4

Outline

New process

Shear modulus, damping ratio Bridgestone, TARRC Vibration attenuation small shaking table automotive suspension bush Lemförder

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New Process

Green & Clean

acid coagulation new process fresh rubber latex

Dampaprene = high damping + polyisoprene

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SLIDE 6

Physical and Mechanical properties

Properties STR 5L ENR 50 Dampaprene 20 Mooney (ML 1+4) 100 0C 77  2 69  2 65  2 Hardness (Shore A) 68  1 69  1 69  1 Tensile strength (MPa) 27.5  0.4 26.5  0.6 24.5  0.6 Elongation at break (%) 537  9 503  13 528  10 100% Modulus (MPa) 3.6  0.1 3.7  0.1 3.4  0.1 300% Modulus (MPa) 15.6  0.2 16.0  0.2 14.5  0.2 Tear strength (N/mm) die B 173  4 98  4 151  3

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Dynamic Properties

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  • 60
  • 40
  • 20

20 40 60 80 100 0.01 0.1 1 Temperature [0C] Tan delta STR 5L ENR 50 Dampaprene 20

  • 80
  • 60
  • 40
  • 20

20 40 60 80 100 10

1

10

2

10

3

10

4

Temperature [0C] Storage Modulus [MPa] STR 5L ENR 5L Dampaprene 20

ENR : high temperature dependence : inapplicable

STR 5L and Dampaprene 20 : Low temperature dependence: applicable

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SLIDE 8
  • 2. Shear modulus & damping ratio : ISO 22762

Bridgestone and TARRC high damping compounds

low modulus high modulus

references

Bridgestone

Chang, Y.W. and Seidensticker, R.W., Argonne National Laboratory, ANL/RE-93/7 (1993)

TARRC

Tun Abdul Razak Research Centre

Burtscher, S.L. and Dorfmann A., Engineering Structures, 26 (2004), 1979-1991

developed compounds

Dampaprene low-modulus

[60 Shore A]

Dampaprene high-modulus

[73 Shore A]

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SLIDE 9

Shear modulus and damping test

rubber

steel

 30 mm. 5 mm.

ISO 22762 0.5 Hz 2-300% strain

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Definition of Stiffness, Shear Modulus, and Damping Ratio

Displacement Total Restoring Force fmax xmax fmin xmin

Stiffness K = xmax - xmin fmax - fmin Damping ratio = 2(Kd2) W W = area within the loop

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G = Kt/A

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SLIDE 11
  • 400
  • 300
  • 200
  • 100

100 200 300 400

  • 4
  • 3
  • 2
  • 1

1 2 3 4 Shear Strain [%] Force [kN] HM-Dampaprene D22 (High Modulus)

  • 400
  • 300
  • 200
  • 100

100 200 300 400

  • 2.0
  • 1.5
  • 1.0
  • 0.5

0.5 1.0 1.5 2.0 Shear Strain [%] Shear Force [kN] LM-Dampaprene D22 (Low Modulus)

Hysteresis Loops

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1 10 100 5 10 15 20 25 Shear Strain [%] Damping Ratio [%] LM-Dampaprene 22 LM-Bridgestone 1 10 100 5 10 15 20 25 Shear Strain [%] Damping Ratio [%] HM-Dampaprene 22 HM-TARRC 1 10 100 1 2 3 4 5 6 7 8 Shear Strain [%] Shear Modulus [MPa] HM-Dampaprene 22 HM-TARRC 1 10 100 0.2 0.4 0.6 0.8 1.0 1.2 Shear Strain [%] Shear Modulus [MPa] LM-Dampaprene 22 LM-Bridgestone

Shear Modulus and Damping Ratio

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SLIDE 13

10 mm. 10 mm. 5 mm. 3 mm. 3 mm. 10 mm 5 mm 50 mm 44 mm

rubber steel shim

M20

  • 3. Vibration attenuation test : cylindrical isolators

small shaking table (laboratory scale)

shape factor ≈ 1.1

STR 5L, ENR, Dampaprene

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Isolators and shaking table 5 Hz, stroke 15 mm, load 200 kg

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SLIDE 15

0.02 0.04 0.06 0.08 0.10 0.12 0.14 0.16 0.18

  • 5
  • 4
  • 3
  • 2
  • 1

1 2 3 4 5

Time [sec] Base Acceleration [g]

Base Excitation 0.02 0.04 0.06 0.08 0.1 0.12 0.14 0.16 0.18

  • 1
  • 0.8
  • 0.6
  • 0.4
  • 0.2

0.2 0.4 0.6 0.8 1

Time [sec] Structure Acceleration [g]

STR 5L ENR Dampaprene 20

Excitation and response signals

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  • 4. Fatigue test : suspension bush : Lemförder

genuine part Lemförder copied part Dampaprene D13

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Fatigue : Stiffness, Damping

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1

  • 5
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1 Displacement [mm] Force [kN] Fatigue [kilocycles] 50 40 30 20 10 1

Lemforder

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1

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1 Displacement [mm] Force [kN] Fatigue [kilocycles] 200 150 100 50 40 30 20 10 1

Dampaprene D13

Changes in Hysteresis Loops with Cycles of Oscillation

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Fatigue : Stiffness, Damping

50 100 150 200 70 75 80 85 90 95 100 Fatigue [kilocycles] Stiffness Retention [%] Dampaprene 13 Lemforder 50 100 150 200 3 4 5 6 7 8 Fatigue [kilocycles] Damping Ratio [%] Dampaprene 13 Lemforder

Dampaprene Suspension bush : workable

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Conclusions

acid coagulation

NR

green clean process

good mechanical strength high damping

limitations / normal practices

high damping high mechanical strength

Dampaprene

low temperature dependence

TARRC Bridgestone

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SLIDE 20

Thank you ?

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