Development of Bond Strength Model for FRP Plates Using Back-Propagation Algorithm

역전파 학습 알고리즘을 이용한 콘크리트와 부착된 FRP 판의 부착강도 모델 개발

  • Received : 2005.07.21
  • Published : 2006.03.30

Abstract

In order to catch out such Bond Strength, the preceding researchers had ever examined the Bond Strength of FRP Plate through their experimentations by setting up of various fluent. However, since the experiment for research on such Bond Strength takes much of expenditure for equipment structure and time-consuming, also difficult to carry out, it is conducting limitedly. This Study purposes to develop the most suitable Artificial Neural Network Model by application of various Neural Network Model and Algorithm to the adhering experiment data of the preceding researchers. Output Layer of Artificial Neural Network Model, and Input Layer of Bond Strength were performed the learning by selection as the variable of the thickness, width, adhered length, the modulus of elasticity, tensile strength, and the compressive strength of concrete, tensile strength, width, respectively. The developed Artificial Neural Network Model has applied Back-Propagation, and its error was learnt to be converged within the range of 0.001. Besides, the process for generalization has dissolved the problem of Over-Fitting in the way of more generalized method by introduction of Bayesian Technique. The verification on the developed Model was executed by comparison with the resulted value of Bond Strength made by the other preceding researchers which was never been utilized to the learning as yet.

FRP 판은 외부 부착된 보강 판의 효과적인 부착강도의 증진으로 실질적으로 부착강도에 대한 많은 연구가 수행되어왔다. 선행연구자들은 이러한 부착강도를 알아보기 위하여 다양한 변수를 설정하여 실험을 통하여 FRP 판의 부착강도를 규명하였다. 그러나, 이러한 부착강도를 알아보기 위한 실험은 장비구축의 비용과 시간 소비가 많이 되고 수행하기 어렵기 때문에 국한적으로 수행되고 있다. 본 연구는 선행연구자들의 부착실험 데이터를 다양한 신경망 모형과 알고리즘을 적용하여 최적의 인공신경망 모형을 개발하는데 그 목적이 있다. 인공신경망 모형의 출력층은 부착강도, 입력층은 FRP 판의 두께, 폭, 부착 길이, 탄성계수, 인장강도와 콘크리트의 압축강도, 인장강도, 폭을 변수로 선정하여 학습을 수행하였다. 개발된 인공신경망 모형은 역전파 학습 알고리즘을 적용하였으며, 오차는 0.001범위에 수렴되도록 학습을 하였다. 또한, 일반화 과정은 Bayesian 기법을 도입함으로써 보다 일반화된 방법으로 과대적합의 문제를 해소하였다. 개발된 모형의 검증은 학습에 이용되지 않은 다른 선행연구자들의 부착강도 결과 값과 비교함으로서 실시하였다.

Keywords

References

  1. 양동석, 박선규, "콘크리트와 부착된 탄소섬유 및 강판의 부착강도 모델", 한국구조물진단학회, 제8권 제2호, 2004, pp. 80-88.
  2. Ren HT, "Study on Basic Theories and Long Time Behavior of Concrete Structures Strengthened by Fiber Reinforced Polymer", Ph. D. thesis, China: Dalian University of Technology, 2003.
  3. Takeo K, Matsushita H, Makizumi T, Nagashima G, 'Bond Characteristics of CFRP Sheets in the CFRP Bonding Technique', In: Proc. of Japan Concrete Institute, Vol 19, No 2, June 1997, pp.1599-1604.
  4. Tan Z, "Experimental Research for RC beam Strengthened with GFRP", Master Thesis, China: Tsinghua University, 2002.
  5. Ueda T, Sato, Asano Y, "Experimental Study on Bond Strength of Continuous Carbon Fiber Sheet", In proc. of 4th International Symposium on Fiber Reinforced Polymer Reinforcement for Reinforced Concrete Structure, SP-188, Famington Hills(NI) ACI, 1999, pp. 407-416.
  6. Wu Zs, Yuan H, Hiroyuki Y, Tashiyuki K, "Experimental /Analytical Study on Interfacial Fracture Energy and Fracture Propagation along FRP-Concrete Interface", In: ACI International SP-201-8, 2001, pp. 133-142.
  7. Yang YX, Yue QR, Hu YC, "Experimental Study on Bond Performance Between Carbon Fiber Sheets and Concrete", Journal of Building Structures, 22(3), 2001, pp. 36-42.
  8. Zhao HD, Zhang Y, Zhao M, "Research on the Bond Performance between CFRP Plate and Concrete", In: Proc. of 1st Conference on FRP-Concrete Structures of China, 2000, pp.247-253.