Journal of the Computational Structural Engineering Institute of Korea (한국전산구조공학회논문집)

Computational Structural Engineering Institute of Korea (한국전산구조공학회)
권호 표지

Nondestructive Defect Detection in Two-dimensional Anisotropic Composite Elastic Bodies Using the Boundary Element Method

경계 요소법을 이용한 2차원 비등방성 복합재료 탄성체의 비파괴 결함 추정

  • Published : 2004.03.01
Download PDF
⟨ Previous Next ⟩

Abstract

In this paper, the defects of two-dimensional anisotropic elastic bodies are identified by using the boundary element method. The use of numerical models that contain only boundary integral terns reduces the dimensionality of the problem by one. This advantage is particularly important in problems such as crack mechanics. Avoiding domain meshing is also particularly advantageous in the solution of inverse problems since it overcomes mesh perturbations and simplifies the procedure. In this paper, nondestructive approaches for the existing isotropic materials are extended to analyze the elastic bodies made of anisotropic materials such as composites. After verifying that the proposing boundary element model is in good agreement with numerical results reported by other investigators, the effect of noise in the measurements on the identifiability is studied with respect to different design parameters of layered composites. Sample studies are carried out for various layup configurations and loading conditions. The effects of the layup sequences in detecting flaw of composites is explored in this paper.

본 연구에서는 경계 요소법을 이용하여 2차원 비등방성 탄성체의 손상 규명을 수행한다. 경계에서의 적분항만을 포함하는 본 수치모델은 1차원으로 줄게된다. 이러한 장점은 특히 균열 역학과 같은 문제에 있어서 중요한 의미를 갖는다. 또한 일정 영역을 분할하는 기법을 피함으로서 수치해석 과정을 간편하고 효율적으로 수행할수 있기 때문에 역문제 해결에 있어서 장점을 갖는다. 본 연구에서는 기존의 등방성 재료에 대한 비파괴 추정기법을 복합신소재와 같은 비등방성 재료로 이루어진 탄성체의 해석에 대하여 확장한다. 먼저 경계요소법에 의한 수치모델의 타당성을 기존의 문헌과 비교 검증하며, 서로 다른 특성을 보이는 비등방성 형식의 변화에 따라 실제 측정시 발생하는 노이즈 영향을 분석한다. 수치예제는 적층 형태 및 하중조건에 대하여 수행하며, 결함 추정에 미치는 적층 형태의 영향을 시험한다.

Keywords

References

  1. AFML-TR-71-268 Interactive program for analysis and design problems in advanced composites technolog Cruse,T.A.;Swedlow,J.L.
  2. J. Fract. v.11 no.2 Boundary-integral equation analysis of cracked anisotropic plates Snyder M.D.;Cruse T.A. https://doi.org/10.1007/BF00038898
  3. J. Numer. Meth. Eng. v.12 no.9 Efficient implementation of anisotropic three dimensional boundary integral equation analysis Wilson R.B.;Cruse T.A. https://doi.org/10.1002/nme.1620120907
  4. J. Solids Struct. v.22 no.26 Two-dimensional time domain beam for scattering of elastic waves in solids of general anisotropy Wang,C.Y.;Achenbach J.D.;Hirose S.
  5. J. Solids Struct. v.29 no.17 Analysis of patched and stiffened cracked panels using the boundary element method Young A.;Rooke D.P.;Cartwright D.J. https://doi.org/10.1016/0020-7683(92)90066-3
  6. Comp Struct. v.66 no.5 Boundary element analysis for composite materials and a library of green's functions Lingyun P.;Daniel O.A.;Frank J.R. https://doi.org/10.1016/S0045-7949(97)00114-4
  7. J. Eng. Anal. B. E. v.25 no.339 Boundary element analysis of cracked panels repaired by mechanically fastened composite patches Widagdo D.;Aliabadi M.H.
  8. J. of Numer Meth Eng. v.36 A boundary element formulation for the inverse elastostatics problem of flaw detection Bezerra L.M.;Saigal S. https://doi.org/10.1002/nme.1620361304
  9. J. of Numer Meth Eng. v.38 Flaw identification using the boundary element method Mellings S.C.;Aliabadi M.H. https://doi.org/10.1002/nme.1620380304
  10. J. Numer Meth Eng. v.49 Numerical solution of the variation boundary integral equation for inverse problems Gallego R.;Suarez J.
  11. Theory of Elasticity of an Anisotropic Body Lekhnitskii S.G.
  12. J. KSCE v.20 no.3-A A Numerical Comparison Study on Natural Vibration and Mode Characteristics of Anisotropic Laminated Composite Plates Lee,S.Y.;Baik H.S.;Chang S.Y.
  13. Boundary Elements in Dynamics CMP Dominguez J.
  14. PhD thesis, University of Garanada Numerical methods for nondestructive identification of defects Rus G.
  15. J. Eng. Anal. B. E. v.26 no.4 Optimization algorithms for identification inverse problems with the boundary element method Rus G.;Gallego R. https://doi.org/10.1016/S0955-7997(02)00008-5