DOI QR코드

DOI QR Code

Aeroelastic testing of a self-supported transmission tower under laboratory simulated tornado-like vortices

  • Ezami, Nima (Department of Civil and Environmental Engineering, The University of Western Ontario) ;
  • El Damatty, Ashraf (Department of Civil and Environmental Engineering, The University of Western Ontario) ;
  • Hamada, Ahmed (Department of Civil and Environmental Engineering, The University of Western Ontario) ;
  • Hangan, Horia (WindEEE Research Institute, The University of Western Ontario)
  • 투고 : 2021.07.11
  • 심사 : 2022.01.03
  • 발행 : 2022.02.25

초록

The current study investigates the dynamic effects in the tornado-structure response of an aeroelastic self-supported lattice transmission tower model tested under laboratory simulated tornado-like vortices. The aeroelastic model is designed for a geometric scale of 1:65 and tested under scaled down tornadoes in the Wind Engineering, Energy and Environment (WindEEE) Research Institute. The simulated tornadoes have a similar length scale of 1:65 compared to the full-scale. An extensive experimental parametric study is conducted by offsetting the stationary tornado center with respect to the aeroelastic model. Such aeroelastic testing of a transmission tower under laboratory tornadoes is not reported in the literature. A multiaxial load cell is mounted underneath the base plate to measure the base shear forces and overturning moments applied to the model in three perpendicular directions. A three-axis accelerometer is mounted at the level of the second cross-arm to measure response accelerations to evaluate the natural frequencies through a free-vibration test. Radial, tangential, and axial velocity components of the tornado wind field are measured using cobra probes. Sensitivity analyses are conducted to assess the variation of the structural dynamic response associated with the location of the tornado relative to the lattice transmission tower. Three different layouts representing the change in the orientation of the tower model relative to the components of the tornado-induced loads are considered. The structural responses of the aeroelastic model in terms of base shear forces, overturning moments, and lateral accelerations are measured. The results are utilized to understand the dynamic response of self-supported transmission towers to the tornado-induced loads.

키워드

과제정보

The authors gratefully acknowledge Hydro One Networks Inc., the Natural Sciences and Engineering Research Council of Canada (NSERC), and Canada Foundation for Innovation (CFI) "WindEEE Dome" project for their collaboration and financial support provided for this research. The authors also gratefully acknowledge the WindEEE Research Institute experts and technicians for their continuous assistance with the testing.

참고문헌

  1. Altalmas, A., El Damatty, A.A. and Hamada, A. (2012), "Progressive failure of transmission towers under tornado loading", CSCE Annual Conference, June.
  2. American Society of Civil Engineers (ASCE) (2020), Guidelines for Electrical Transmission Line Structural Loading, ASCE Manuals and Reports on Engineering Practice, No. 74, New York, NY, U.S.A.
  3. Ashrafi, A., Romanic, D., Kasab, A., Hangan, H. and Ezami, N. (2021), "Experimental investigation of large-scale tor-nado-like vortices", J. Wind Eng. Ind. Aerod., 208, 104449. https://doi.org/10.1016/j.jweia.2020.104449
  4. Australian Standard/New Zealand Standard (AS/NZS) 7000 (2010), Overhead Line Design Detailed Procedures, Standards Australia Limited/Standards New Zealand, North Sydney, Australia
  5. Baker, G.L. and Church, C.R. (1979), "Measurements of core radii and peak velocities in modeled atmospheric vortices", J. Atmos. Sci., 36, 2413-2424. https://doi.org/10.1175/1520-0469(1979)036%3C2413:MOCRAP%3E2.0.CO;2.
  6. Behncke, R.H. and White, H.B. (2006), "Applying gust loadings to your lines", Proceedings of the 9th International Conference on Overhead Lines, Fort Collins, ASCE, CO, U.S.A.
  7. Church, C.R., Snow, J.T. and Agee, E.M. (1977), "Tornado vortex simulation at Purdue University", Bull. Amer. Meteor. Soc. 58, 900-908. https://doi.org/10.1175/1520-0477(1977)058%3C0900:TVSAPU%3E2.0.CO;2.
  8. Church, C.R., Snow, J.T., Baker, G.L. and Agee, E.M. (1979), "Characteristics of tornado-like vortices as a function of swirl ratio: A laboratory investigation", J. Atmos. Sci. 36, 1755-1776. https://doi.org/10.1175/15200469(1979)036%3C1755:COTLVA%3E2.0.CO;2.
  9. Davies-Jones, RP. (1973), "The dependence of core radius on swirl ratio in a tornado simulator", J. Atmos. Sci. 30, 1427-1430. https://doi.org/10.1175/15200469(1973)030%3C1427:TDOCRO%3E2.0.CO;2.
  10. Dempsey, D. and White, H.B. (1996), "Winds wreak havoc on lines", Transm. Distrib. World, 48(6), 32-42.
  11. El Damatty, A.A. and Hamada, A. (2016), "F2 tornado velocity profiles critical for transmission line structures", Eng. Struct., 106, 436-449. https://doi.org/10.1016/j.engstruct.2015.10.020.
  12. El Damatty, A.A., Hamada, M. and Hamada, A. (2015), "Simplified F2 tornado load cases for transmission line structures", 14th International Conference on Wind Engineering, ICWE14, Porto Alegre, Brazil.
  13. Fujita, T.T. (1981), "Tornadoes and downbursts in the context of generalized planetary scales", J. Atmos. Sci. 38, 1511-1534. https://doi.org/10.1175/15200469(1981)038%3C1511:TADITC%3E2.0.CO;2.
  14. Fujita, T.T. and Pearson, A.D. (1973), "Results of FPP classification of 1971 and 1972 tornadoes", The 8th Conference on Severe Local Storms, U.S.A.
  15. Haan, F.L., Sarkar, P.P. and Gallus, W.A. (2008), "Design, construction and performance of a large tornado simulator for wind engineering applications", Eng. Struct. 30, 1146-1159. https://doi.org/10.1016/j.engstruct.2007.07.010.
  16. Hamada, A. and El Damatty, A.A. (2011), "Behaviour of guyed transmission line structures under tornado wind loading", Comput. Struct. 89(11-12), 986-1003. https://doi.org/10.1016/j.compstruc.2011.01.015.
  17. Hamada, A. and El Damatty, A.A. (2015), "Failure analysis of guyed transmission lines during f2 tornado event", Eng. Struct., 85(15), 11-25. https://doi.org/10.1016/j.engstruct.2014.11.045.
  18. Hamada, A., El Damatty, A.A., Hangan, H. and Shehata, A.Y. (2010), "Finite element modelling of transmission line structures under tornado wind loading", Wind Struct. 13(5), 451-469. https://doi.org/10.12989/was.2010.13.5.451.
  19. Hamada, A., King, J.P.C., El Damatty, A.A., Bitsuamlak, G. and Hamada, M. (2017), "The response of a guyed transmission line system to boundary layer wind", Eng. Struct. 139, 135-152. https://doi.org/10.1016/j.engstruct.2017.01.047.
  20. Hangan H. and Kim, J. (2008), "Swirl ratio effects on tornado vortices in relation to the Fujita scale", Wind Struct., 11(4), 291-302. https://doi.org/10.12989/was.2008.11.4.291.
  21. Kosiba, K. and Wurman, J. (2010), "The three-dimensional axisymmetric wind field structure of the he Spencer, South Dakota, 1998 tornado", J. Atmos. Sci., 67(9), 3074-3083. https://doi.org/10.1175/2010JAS3416.1.
  22. Kosiba, K.A. and Wurman, J. (2013), "The three-dimensional structure and evolution of a tornado boundary layer", Weather Forecast, 28(6), 1552-1561. https://doi.org/10.1175/WAF-D13-00070.1.
  23. Lee, W.C., Jou, B.J., Chang, P.L. and Deng, S.M. (1999), "Tropical cyclone kinematic structure retrieved from single-Doppler radar observations. Part I: Doppler velocity patterns and the GBVTD technique", Month. Weath. Rev. 127(10), 2419-2439. https://doi.org/10.1175/1520-0493(1999)127%3C2419:TCKSRF%3E2.0.CO;2.
  24. Lund, D.E. and Snow, J. (1993), "The tornado: its structure, dynamics, prediction and hazards", Geophys. Monogr. Ser., 79, 297-306. https://ui.adsabs.harvard.edu/link_gateway/1993GMS....79.....C/doi:10.1029/GM079.
  25. McCarthy, P. and Melsness, M. (1996), "Severe weather elements associated with September 5, 1996 hydro tower failures near Grosse Isle, Manitoba", Manitoba Environmental Service Centre, Environment Canada.
  26. Mishra, A.R., James, D.L. and Letchford, C.W. (2008), "Physical simulation of a single-celled tornado-like vortex, Part A: Flow field characterization", J. Wind Eng. Ind. Aerod., 96(8-9), 1243-1257. https://doi.org/10.1016/j.jweia.2008.02.063.
  27. Refan, M. and Hangan, H. (2018), "Near surface experimental exploration of tornado vortices", J. Wind Eng. Ind. Aerod., 175, 120-135. https://doi.org/10.1016/j.jweia.2018.01.042.
  28. Refan, M., Hangan, H. and Wurman, J. (2014), "Reproducing tornadoes in laboratory using proper scaling", J. Wind Eng. Ind. Aerod., 135, 136-148. https://doi.org/10.1016/j.jweia.2014.10.008.
  29. Refan, M., Hangan, H., Wurman, J. and Kosiba, K. (2017), "Doppler radar-derived wind field of several tornadoes with application to engineering simulations", Eng. Struct., 148, 509-521. https://doi.org/10.1016/j.engstruct.2017.06.068.
  30. Rotunno, R. (1979), "A Study in tornado-like vortex dynamics", J. Atmos. Sci., 36(1), 140-155. https://doi.org/10.1175/1520-0469(1979)036%3C0140:ASITLV%3E2.0.CO;2.
  31. Sarkar, P., Haan, F., Gallus, W. Jr., Le, K. and Wurman J. (2005), "Velocity measurements in a laboratory tornado simulator and their comparison with numerical and fullscale data", 37th Joint meeting panel on wind and seismic effects, Tsukuba, Japan.
  32. Savory, E., Parke, G.A.R., Zeinoddini, M., Toy, N. and Disney, P. (2001), "Modelling of tornado and microburst-induced wind loading and failure of a lattice transmission tower", Eng. Struct., 23(4), 365-375. https://doi.org/10.1016/S0141-0296(00)00045-6.
  33. Tian, L. and Zeng, Y. (2016), "Parametric study of tuned mass dampers for long span transmission tower-line system under wind loads", Shock Vib., 2016, https://doi.org/10.1155/2016/4965056.
  34. Wakimoto, R.M., Atkins, N.T. and Wurman, J. (2011), "The LaGrange tornado during VORTEX2. Part I: Photogrammetric analysis of the tornado combined with single-Doppler radar data", Month. Weath. Rev. 139, 2233-2258. https://doi.org/10.1175/2010MWR3568.1.
  35. Wang, H., James, D., Letchford, C.W., Peterson, R. and Snow, J. (2001), "Development of a prototype tornado simulator for the assessment of fluid-structure interaction", First American Conference on Wind Engineering, Clemson, SC.
  36. Ward, N.B. (1972), "The exploration of certain features of tornado dynamics using a laboratory model", J. Atmos. Sci., 29, 1194-1204. https://doi.org/10.1175/1520-0469(1972)029%3C1194:TEOCFO%3E2.0.CO;2.
  37. Wurman, J. and Gill, S. (2000), "Finescale radar observations of the dimmitt, Texas (2 June 1995), Tornado", Month. Weath. Rev., 128(7), 2135-2164. https://doi.org/10.1175/1520-0493(2000)128%3C2135:FROOTD%3E2.0.CO;2.