Transactions of the Korean Society of Mechanical Engineers A (대한기계학회논문집A)

The Korean Society of Mechanical Engineers (대한기계학회)
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Development of an Inverse Method Using Orthogonal Basis Functions for the Evaluation of Boundary Tractions on an Elastic Body

탄성체 경계 트랙션을 구하는 문제에서 상호 수직 기저 함수를 사용한 역문제 해석 방법의 개발

  • Kim, Sa-Young (The graduate school of Energy & Environment, Seoul Nat'l Univ. of Technology) ;
  • Kim, Hyun-Gyu (Dept. of Mechanical Engineering, Seoul Nat'l Univ. of Technology)
  • 김사영 (서울산업대학교 에너지환경대학원) ;
  • 김현규 (서울산업대학교 기계공학과)
  • Published : 2010.04.01
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Abstract

Most structural analyses are concerned with the deformations and stresses in a body subjected to external loads. However, in many fields, inverse problems have to be interpreted to determine surface tractions or internal stresses from displacements measured on a remote surface. In this study, the inverse processes are studied by using the finite element method for the evaluation of internal stresses. Small errors in the measured displacements often result in a substantial loss of stability of an inverse system. In order to improve the stability of the inverse system, the displacements on a section near the region of the unknown tractions are predicted by using orthogonal basis functions. We use the Gram-Schmidt orthogonal technique to determine two bases for the displacements on a section near the region of the unknown tractions. Advantages over previous methods are discussed by using numerical examples.

대부분의 구조해석 문제는 외부에서 주어진 하중에 대한 변형과 응력에 관심을 두고 있지만 많은 경우에서 표면 또는 내부에 주어진 응력이나 트랙션을 구하는 역문제 해석이 필요하게 된다. 본 연구에서는 구하고자 하는 트랙션에서 멀리 떨어진 영역의 변위를 측정하여 미지의 트랙션을 평가하는데 유한요소법을 사용한 역문제 수식화를 적용하였다. 일반적으로 역시스템의 불안정으로 인하여 측정 변위의 작은 오차는 해석 결과에 큰 영향을 주게 된다. 이와 같은 역시스템의 불안정성을 개선하기 위하여 본 연구에서는 구하고자 하는 트랙션에 가까운 단면의 변위를 Gram-Schmidt 수직화 기법을 통한 수직기저함수 사용하여 예측하고 보다 안정된 역문제를 해석하는 방법을 개발하였고 장점들을 수치 예제를 통하여 보여주었다.

Keywords

References

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