The optimal design of the mounting rubber system for reducing vibration of the air compressor focusing on complex dynamic stiffness


Urban rapid railway is one of the most popular transportation methods these days. It is equipped with large-capacity air compressors since it uses pneumatic pressure to supply power for braking and for opening and closing doors. Passengers tend to complain about vibration and noise from the air compressor. In this study, vibration reduction of air compressor was achieved by acquiring exact complex dynamic stiffness of the mounting rubber and optimizing the shape of it. Target stiffness values of the rubber was obtained from multi-body dynamics simulation of the air compressor-mounting system. Complex elastic modulus of the rubber mount was derived through EMA and Gent’s method and verified by finite element method. Through parametric study of mounting rubber, an optimal shape of mounting rubber was derived and produced. Lastly, the proposed value was verified by experiments comparing with baseline value.

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Cross-sectional area of the rubber


Complex elastic modulus


Elastic modulus


Force to rubber


Magnitude of force

kaxial :

Stiffness in axial direction

kradial :

Stiffness in radial direction


Complex stiffness


Magnitude of complex stiffness


Length of the rubber


Shape factor of the rubber


Displacement of rubber


Magnitude of displacement


Loss angle


Loss factor


  1. [1]

    B. Challen and R. Baranescu, Diesel Engine Reference Book, Butterworth Heinemann (1999).

  2. [2]

    N. Yu, N. Naganathan and R. Dukkipatit, Review of automotive vehicle engine mounting systems, International J. of Vehicle Design, 24(4) (2000) 299–319.

    Article  Google Scholar 

  3. [3]

    K. Kim, U. Park and W. Lee, Prediction of transfer force of railway air compressor using transfer path analysis, J. of the Korean Society for Railway, 22(2) (2019) 101–108.

    Article  Google Scholar 

  4. [4]

    T. Jeong and R. Singh, Analytical methods of decoupling the automotive engine torque roll axis, J. of Sound and Vibration, 234(1) (2000) 85–114.

    Article  Google Scholar 

  5. [5]

    J. Y. Park and R. Singh, Effect of non-proportional damping on the torque roll axis decoupling of an engine mounting system, J. of Sound and Vibration, 313 (2008) 841–857.

    Article  Google Scholar 

  6. [6]

    C. E. Spiekermann, C. J. Radcliffe and E. D. Goodman, Optimal design and simulation of vibrational isolation systems, J. of Mechanisms, Transmissions and Automation in Design, 107 (1985) 271–276.

    Article  Google Scholar 

  7. [7]

    J. S. Tao, G. R. Liu and K. Y. Lam, Design optimization of marine engine-mount system, J. of Sound and Vibration, 235(3) (2000) 477–494.

    Article  Google Scholar 

  8. [8]

    J. S. Tao, G. R. Liu and K. Y. Lam, Excitation force identification of an engine with velocity data at mounting points, J. of Sound and Vibration, 242(2) (2001) 321–331.

    Article  Google Scholar 

  9. [9]

    J. S. Tao, G. R. Liu and K. Y. Lam, Dynamic analysis of a rigid body mounting system with flexible foundation subject to fluid loading, Shock and Vibration, 8(1) (2001) 33–47.

    Article  Google Scholar 

  10. [10]

    D. Koblar, J. Skofic and M. Boltezar, Evaluation of the Young’s modulus of rubber-like materials bonded to rigid surfaces with respect to Poisson’s ratio, J. of Mechanical and Engineering, 60(7) (2014) 61–71.

    Google Scholar 

  11. [11]

    Y. H. Lee, Study on dynamic characteristics prediction of rubber components for improvement of vehicle vibration performance, Ph.D. Thesis, Hanyang University (2009).

  12. [12]

    S. O. Oyadiji and G. R. Tomlison, Determination of the complex moduli of viscoelastic structural elements by resonance and non-resonance methods, J. of Sound and Vibration, 101(3) (1985) 277–298.

    Article  Google Scholar 

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This research was supported by 2019 Hongik University Research Fund and a grant (20RTRP-B148337-03) from “Development of high-performance interchangeable standard flexible brake pads and shoes for power concentrated high speed trains” funded by Ministry of land, Infrastructure and Transport of Korean government.

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Corresponding author

Correspondence to Kwanju Kim.

Additional information

Uyeup Park is a M.S. candidate in Mechanical Engineering at Hongik University. He received his B.S. in Mechanical and System Engineering at Hongik University. His research interests include vibration reduction of compressor and optimization algorithm.

Jun Heon Lee is a Ph.D. candidate in Mechanical Engineering at Hongik University. He received his M.S. in Mechanical Engineering at Hongik University in 2013. His research interests are NVH analysis and EMA.

Kwanju Kim is a Professor of Mechanical and System Engineering at Hongik University. He received his Ph.D. in Mechanical Engineering from Stanford University in 1987. He worked as a Senior Researcher at Kia motors research center in 1988`-1992. His research field is NVH issues of transportation.

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Park, U., Lee, J.H. & Kim, K. The optimal design of the mounting rubber system for reducing vibration of the air compressor focusing on complex dynamic stiffness. J Mech Sci Technol 35, 487–493 (2021).

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  • Air compressor
  • Mounting rubber
  • Vibration reduction
  • Parametric study
  • Shape optimization