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

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 bearing seismic bearing dock fender suspension bush Damping ratio ≤ 10% : normal damping 10% < Damping ratio ≤ 15% : high damping Damping ratio > 15% : super-high damping 3

Outline New process Vibration attenuation Shear modulus, damping ratio automotive suspension bush small shaking table Bridgestone, TARRC 4 Lemförder

New Process acid coagulation new process Green & Clean fresh rubber latex Dampaprene = high damping + polyisoprene 5

Physical and Mechanical properties Properties STR 5L ENR 50 Dampaprene 20 77  2 69  2 65  2 Mooney (ML 1+4) 100 0 C 68  1 69  1 69  1 Hardness (Shore A) 27.5  0.4 26.5  0.6 24.5  0.6 Tensile strength (MPa) 537  9 503  13 528  10 Elongation at break (%) 3.6  0.1 3.7  0.1 3.4  0.1 100% Modulus (MPa) 15.6  0.2 16.0  0.2 14.5  0.2 300% Modulus (MPa) 173  4 98  4 151  3 Tear strength (N/mm) die B 6

Dynamic Properties 4 10 STR 5L ENR 5L 1 Dampaprene 20 Storage Modulus [MPa] 3 10 Tan delta 0.1 2 10 STR 5L ENR 50 Dampaprene 20 1 10 0.01 -80 -60 -40 -20 0 20 40 60 80 100 -80 -60 -40 -20 0 20 40 60 80 100 Temperature [ 0 C] Temperature [ 0 C] ENR : high temperature dependence : inapplicable STR 5L and Dampaprene 20 : Low temperature dependence: applicable 7

2. Shear modulus & damping ratio : ISO 22762 Bridgestone and TARRC high damping compounds low modulus high modulus Bridgestone TARRC Tun Abdul Razak Research references Centre Burtscher, S.L. and Dorfmann A., Chang, Y.W. and Seidensticker, Engineering Structures , 26 (2004), R.W., Argonne National Laboratory, 1979-1991 ANL/RE-93/7 (1993) Dampaprene Dampaprene low-modulus high-modulus developed compounds [60 Shore A] [73 Shore A] 8

Shear modulus and damping test rubber 5 mm .  30 mm . steel ISO 22762 0.5 Hz 2-300% strain 9

Definition of Stiffness, Shear Modulus, and Damping Ratio f max Total Restoring Force x min 0 x max W = area within the loop f min 0 Displacement f max - f min G = Kt/A Stiffness K = x max - xmin W Damping ratio = 2  ( K d 2 ) 10

Hysteresis Loops 2.0 4 LM-Dampaprene D22 1.5 3 HM-Dampaprene D22 (Low Modulus) 1.0 (High Modulus) 2 Shear Force [kN] 0.5 1 Force [kN] 0 0 -0.5 -1 -1.0 -2 -1.5 -3 -2.0 -4 -400 -300 -200 -100 0 100 200 300 400 -400 -300 -200 -100 0 100 200 300 400 Shear Strain [%] Shear Strain [%] 11

Shear Modulus and Damping Ratio 1.2 8 LM-Dampaprene 22 7 HM-Dampaprene 22 1.0 LM-Bridgestone HM-TARRC Shear Modulus [MPa] Shear Modulus [MPa] 6 0.8 5 0.6 4 3 0.4 2 0.2 1 0 0 1 10 100 1 10 100 Shear Strain [%] Shear Strain [%] 25 25 20 20 Damping Ratio [%] Damping Ratio [%] 15 15 10 10 HM-Dampaprene 22 HM-TARRC LM-Dampaprene 22 5 5 LM-Bridgestone 12 0 0 1 10 100 1 10 100 Shear Strain [%] Shear Strain [%]

3. Vibration attenuation test : cylindrical isolators small shaking table (laboratory scale) M20 5 mm 10 mm rubber 3 mm . 10 mm . 44 mm steel shim 3 mm . 10 mm . 5 mm . STR 5L, ENR, Dampaprene 50 mm shape factor ≈ 1.1 13

Isolators and shaking table 5 Hz, stroke 15 mm, load 200 kg 14

Excitation and response signals 5 1 Base Excitation STR 5L 4 0.8 ENR Dampaprene 20 3 0.6 Structure Acceleration [g] Base Acceleration [g] 2 0.4 1 0.2 0 0 -0.2 -1 -0.4 -2 -0.6 -3 -0.8 -4 -1 -5 0 0.02 0.04 0.06 0.08 0.10 0.12 0.14 0.16 0.18 0 0.02 0.04 0.06 0.08 0.1 0.12 0.14 0.16 0.18 Time [sec] Time [sec] 15

4. Fatigue test : suspension bush : Lemförder genuine part copied part Lemförder Dampaprene D13 16

Changes in Hysteresis Loops with Cycles of Oscillation Fatigue : Stiffness, Damping 1 1 Dampaprene D13 Lemforder 0 0 -1 -1 Force [kN] Force [kN] Fatigue [kilocycles] -2 Fatigue [kilocycles] -2 200 150 50 100 40 -3 50 -3 30 40 20 30 10 20 -4 -4 1 10 1 -5 -5 -5 -4 -3 -2 -1 0 1 -5 -4 -3 -2 -1 0 1 Displacement [mm] Displacement [mm] 17

Fatigue : Stiffness, Damping 100 8 95 7 Stiffness Retention [%] Damping Ratio [%] 90 6 85 Dampaprene 13 5 Lemforder Dampaprene 13 80 Lemforder 4 75 3 70 0 50 100 150 200 0 50 100 150 200 Fatigue [kilocycles] Fatigue [kilocycles] Dampaprene Suspension bush : workable 18

Conclusions acid coagulation NR limitations / Bridgestone normal practices green clean process TARRC Dampaprene good mechanical strength low temperature dependence high mechanical strength high damping high damping 19

Thank you ? 20