Structural Monitoring and Maintenance

Techno-Press (테크노프레스)
권호 표지
DOI QR코드

DOI QR Code

Multi-dimensional seismic response control of offshore platform structures with viscoelastic dampers (II-Experimental study)

  • He, Xiao-Yu (Zhejiang Provincial Planning, Design & Research Institute of Communications) ;
  • Zhao, Tie-Wei (Ningbo Port and Waterway Administration) ;
  • Li, Hong-Nan (State Key Laboratory of Coastal and Offshore Engineering, Dalian University of Technology) ;
  • Zhang, Jun (State Grid Zhejiang Electric Power Company)
  • Received : 2015.12.31
  • Accepted : 2016.03.25
  • Published : 2016.06.25
⟨ Previous Next ⟩

Abstract

Based on the change of traditional viscoelastic damper structure, a brand-new damper is designed to control simultaneously the translational vibration and the rotational vibration for platforms. Experimental study has been carried out on the mechanical properties of viscoelastic material and on its multi-dimensional seismic response control effect of viscoelastic damper. Three types of viscoelastic dampers with different shapes of viscoelastic material are designed to test the influence of excited frequency, strain amplitude and ambient temperature on the mechanical property parameters such as circular dissipation per unit, equivalent stiffness, loss factor and storage shear modulus. Then, shaking table tests are done on a group of single-storey platform systems containing one symmetric platform and three asymmetric platforms with different eccentric forms. Experimental results show that the simulation precision of the restoring force model is rather good for the shear deformation of viscoelastic damper and is also satisfied for the torsion deformation and combined deformations of viscoelastic damper. The shaking table tests have verified that the new-type viscoelastic damper is capable of mitigating the multi-dimensional seismic response of offshore platform.

Keywords

References

  1. Bergman, D.M. and Hanson, R.D. (1993), "Viscoelastic mechanical damping devices tested at real earthquake displacements", Earthq. Spectra, 9(3), 389-417. https://doi.org/10.1193/1.1585722
  2. Bi, J. J. (1989), Offshore Mechanics(in Chinese), Shanghai, Tongji University Press.
  3. Chang, K. C. and Soong, T.T. et al. (1995), "Seismic behavior of steel frame with added viscoelastic dampers", J. Struct. Eng. - ASCE, 121(10), 1418-1426. https://doi.org/10.1061/(ASCE)0733-9445(1995)121:10(1418)
  4. Chang, K.C. and Soong, T.T. et al. (1992), "Ambient temperature on a viscoelastically damped structure", J. Struct. Eng. - ASCE, 118(7), 1955-1973. https://doi.org/10.1061/(ASCE)0733-9445(1992)118:7(1955)
  5. Lee, H.H. (1997), "Stochastic analysis for offshore structures with added mechanical dampers", Ocean Eng., 24(9), 817-834. https://doi.org/10.1016/S0029-8018(96)00039-X
  6. Lin, R.C. and Liang, Z. et al. (1991), "An experimental study on seismic behavior of viscoelastically damped structures", Eng. Struct., 13(1), 75-84. https://doi.org/10.1016/0141-0296(91)90011-Z
  7. Ma, H.L. and Lu, J.H. et al. (2004), "Viscoelastic damper vibration control of platform with pole assignment technique(in Chinese)", J. Ship Mech., 8(4), 116-120.
  8. Mahmoodi, P. (1969), "Structural dampers", J. Struct. Eng. Div. - ASCE, 95(10), 1661-1672.
  9. Ou, J.P. and Duan, Z.D. et al. (1999), "Ice-induced vibration analysis of JZ20-2MUQ offshore platform using in-situ ice force histories (in Chinese)", Ocean Eng., 17(2), 70-78.
  10. Ou, J.P. and Xiao, Y.Q. et al. (2000), "Ice-induced vibration control of JZ20-2MUQ Platform Structure with viscoelastic energy dissipators (in Chinese)", Ocean Eng., 18(3), 9-14.
  11. Ou, J.P. and Xu, L. et al. (2002), "Damping isolation system and its vibration-suppressed effectiveness analysis for offshore platform jacket structures (in Chinese)", Earthq. Eng. Eng. Vib., 22(3), 115-122.
  12. Zhou, Y. (2006), Damping structral design by viscoelastic damper(in Chinese), Wuhan University of Technology Press, Wuhan, China.