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Electromechanical Relation of Conductive Materials with High Electrical Resistance and Its Application to the Estimation of In_situ Stress of Structural Tendons

고저항 전도체의 전기기계적 상관작용과 작용응력 예측이 가능한 긴장재의 제안

  • 지광습 (고려대학교 사회환경시스템공학과) ;
  • 전기우 (고려대학교 사회환경시스템공학과)
  • Received : 2005.11.04
  • Accepted : 2006.02.14
  • Published : 2006.03.30

Abstract

It is proposed that the electromechanical relation of the conductive materials with high electrical resistance may be used to estimate the current stress of prestressing tendons. To choose the best conductive material to this end, we studied the electromechanical relations of carbon fibers and metalic heat wires experimentally. The strain of those materials was controlled instead of the stress during the experiment. It is found that the relation of carbon fibers can be modelled by a parabolic(or hyperbolic) function in the early stage of deformation. However because the relation is not consistent when it is unloaded and reload, carbon fibers are not suitable for this purpose. Metallic heat wires show a consistent linear relation during loading and unloading in the elastic deformation and are suitable for this purpose. To estimate the electromechanics relation of metallic wires, we developed a simple formula based on the rigid plasticity. We propose a new kind of prestressing tendons whose stress can be monitored. As a side result of this study, we found that the electromechanical relation of carbon fibers without epoxy matrix becomes almost linear after a certain strain.

프리스트레스 긴장재에 현재 작용하고 있는 응력을 계측하는 방법으로서 고저항 전도체의 전기기계적 상관작용을 이용하는 방법을 제안했다. 사용 고저항 전도체를 선택하기 위해 탄소섬유와 금속계 열선의 특성을 일반적인 응력제어와는 달리 변형률제어를 통해 실험적으로 연구했다. 탄소섬유의 경우 변형 초기에는 일반적으로 알려진 포물선 형태의 상관관계를 보였으나 재하-제하시 상관관계의 기울기가 일정하지 않아서 본 목적에는 부합하는 않는 것으로 확인되었다. 금속계 열선은 거의 전 구간에서 탄성 재하, 제하 및 재재하시 일정한 선형 상관계수를 보여 본 목적에 매우 적합한 것으로 확인되었다. 금속계열선의 전기기계적 상관관계를 예측하기 위해 완전소성론에 기초한 간단한 식을 제안하였다. 또한 금속계 열선을 이용한 긴장력 측정이 가능한 긴장재를 최초로 제안했다. 본 연구의 부수적인 결과로서 함침되지 않은 탄소섬유의 경우, 특정 변형률 이후 추가 변형에 대해 거의 선형적인 전기기계적 상관관계를 갖는 새로운 경향을 발견했다.

Keywords

References

  1. 신호상 (1999) 프리스트레스력 측정방법에 대하여. 건설기술정보, 한국건설기술연구원, 통권191호 pp. 6-11
  2. Abry, J. C., Bochard, S., Chateauminois, A., Salvia, M., and Giraud, G. (1999) In situ detection of damage in CFRP laminates by electrical resistance measurements. Comput Sci. Technol., Vol. 59, No.6, pp. 925-935 https://doi.org/10.1016/S0266-3538(98)00132-8
  3. Abry, J. C., Choi, Y. K., Chateauminois, A., Dalloz, B., Giraud, G, and Salvia, M. (2000) In-situ monitoring of damage in CFRP laminates by means of AC and DC measurements. Comput Sci. Technol. Vol. 61, No.6, pp. 855-864 https://doi.org/10.1016/S0266-3538(00)00181-0
  4. Angelidis, N., Wei, C. Y., and Irving, P. E. (2004) The electrical resistance response of continuous carbon fibre composites laminate to mechanical strain. Composites A, Vol. 35, No, 10, pp. 1135-1147 https://doi.org/10.1016/j.compositesa.2004.03.020
  5. Azizinamini, A., Keeler, B. J., Rohde J., and Mehrabi, A. B. (1996) Application of a New Nondestructive Evaluation Technique to a 25-Year-Old Prestressed Concrete Girder. PCI Journal, Vol. 41, No.3, pp. 82-95
  6. Chen, H.-L. and Wissawapaisal, K. (2001) Measurement of tensile forces in a seven-wire prestressing strand using stress waves. J Eng. Mech., Vol. 127, No.6, pp. 599-606 https://doi.org/10.1061/(ASCE)0733-9399(2001)127:6(599)
  7. Chen, H.-L. and Wissawapaisal, K. (2002) Application of wignerville transform to evaluate tensile forces in seven-wire prestressing strands. J. Eng. Mech., Vol. 128, No. 11, pp. 1206-1214 https://doi.org/10.1061/(ASCE)0733-9399(2002)128:11(1206)
  8. Cho, J. W. and Choi, J. S. (2000) Relationship between electrical resistance and strain of carbon fibers upon loading. J. App. Polym. Sci., Vol. 77, No.9, pp. 2082-2087 https://doi.org/10.1002/1097-4628(20000829)77:9<2082::AID-APP26>3.0.CO;2-W
  9. Civjan, S. A., Jirsa, O., Carrasquillo, R. L. and Fowler, D. W. (1995) Method to Evaluation Remaining Prestress in Damaged Prestressed Bridge Girders, Texas Department of Transportation
  10. di Scalea, F. L., Rizzo, P. and Seible, F. (2003) Stress measurement and defect detection in steel strands by guided stress waves. J. Mater. Civil. Eng., Vol. 15, No.3, pp. 219-227 https://doi.org/10.1061/(ASCE)0899-1561(2003)15:3(219)
  11. Kim, S. J., Kim, M. S., Shin, S. R., Kim, I. Y., Kim, S. I., Lee, S. H., Lee, T. S. and Spinks, G. M. (2005) Enhancement of the electromechanical behavior of IPMCs based on chitosan/polyaniline ion exchange membranes fabricated by freeze-drying. Smart Mater Struct., Vol. 14, No.5, pp. 889-894 https://doi.org/10.1088/0964-1726/14/5/025
  12. Kupke, M., Schulte, K., and Schuler, R. (2001) Non-destructive testing of FRP by D.C. and A.C. electrical methods. Comput Sci. Technol. Vol. 61, No.6, pp. 837-847 https://doi.org/10.1016/S0266-3538(00)00180-9
  13. Li, H., Zhou, W. S., and Ou, J. P. (2004) Study on electromechanical behavior of unidirectional carbon fibre sheet without epoxy resin matrix. Adv. Struct. Eng., Vol. 7, No.5, pp. 437-445 https://doi.org/10.1260/1369433042863288
  14. Nemat-Nasser, S. and Li, J. Y. (2000) Electromechanical response of ionic polymer-metal composites. J. Appl. Phys., Vol. 87, No. 7, pp. 3321-3331 https://doi.org/10.1063/1.372343
  15. Park, J. B., Okabe, T., and Takeda, N. (2003) New concept for modeling the electromechanical behavior of unidirectional carbon-fiber-reinforced plastic under tensile loading. Smart mater. struct., Vol. 12 No. 1, pp. 105-114 https://doi.org/10.1088/0964-1726/12/1/312
  16. Park, J. B., Okabe, T., Takeda, N., and Curtin, W. A. (2002) Electromechanical modeling of unidirectional CFRP composites under tensile loading condition. Composites A, Vol. 33, No.2, pp. 267-275 https://doi.org/10.1016/S1359-835X(01)00097-5
  17. Prasse, T., Michel, F., Mook, G, Schulte, K., and Bauhofer, W.A (2001) A comparative investigation of electrical resistance and acoustic emission during cyclic loading of CFRP laminates. Comput. Sci. Technol., Vol. 61, No.6, pp. 831-835 https://doi.org/10.1016/S0266-3538(00)00179-2
  18. Saiidi, M., Douglas, B., and Feng, S. (1994) Prestress Force Effect on Vibration Frequency of Concrete Bridges. J. Struct. Eng., ASCE, Vol. 120, No.7, pp. 2233-2240 https://doi.org/10.1061/(ASCE)0733-9445(1994)120:7(2233)
  19. Sevostianov, I. and Kachanov, M. (2000) Microcracking in Piezoelectrics Weakens the Electromechanical Coupling and Changes Its Directionality. Int. J. fracture., Vol. 101, No.3, pp. 1-8
  20. Xu, M. X., Liu, W. G, Gao, Z. X., Fang, L. P., and Yao, K. D. (1996) Correlation of change in electrical resistance with strain of carbon fiber-reinforced plastic in tension. J. App. Polym. Sci., Vol. 60, No. 10, pp. 1595-1599 https://doi.org/10.1002/(SICI)1097-4628(19960606)60:10<1595::AID-APP11>3.0.CO;2-4