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

The Korean Society of Mechanical Engineers (대한기계학회)
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Study of the Shape Optimization in Spline FEM Considering both NURBS Control Point Positions and Weights as Design Variables

NURBS 제어점의 위치 및 가중치를 설계변수로 하는 스플라인 유한요소법 기반 형상최적설계 연구

  • Song, Yeo-Ul (School of Mechanical, Aerospace and Systems Engineering, Division of Mechanical Engineering, KAIST) ;
  • Hur, Jun Young (School of Mechanical, Aerospace and Systems Engineering, Division of Mechanical Engineering, KAIST) ;
  • Youn, Sung-Kie (School of Mechanical, Aerospace and Systems Engineering, Division of Mechanical Engineering, KAIST)
  • Received : 2013.10.14
  • Accepted : 2014.01.27
  • Published : 2014.04.01
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Abstract

A new NURBS-based shape optimization method is proposed. Most shape optimization studies consider only control point positions as design variables. Some shape optimization processes present problems with mesh quality and convergence when control points are constrained to a limited space. If the weights of the control points are regarded as additional design variables, it should be possible to attain a better degree of shape control. In this study, positions and weights of NURBS control points are used as design variables, and a shape optimization algorithm incorporates position optimization and weight optimization steps. This method is applied to shape optimization benchmarking problems to verify its advantages.

본 연구에서는 NURBS(Non-Uniform Rational B-spline)를 이용한 형상최적화 방법을 제안한다. 대부분 NURBS 기반 형상 최적화 방법은 NURBS의 제어점 위치 좌표 값만을 설계변수로 택하고 있다. 이러한 경우, 형상최적화 과정에서 종종 제어점들이 서로 가까워져 메쉬 품질을 악화시키고 수렴이 되지 않는 등의 문제를 야기시킨다. 본 연구에서는 형상최적화에서 NURBS 제어점의 좌표뿐 아니라 가중치를 추가적으로 설계 변수로 고려하여 세밀한 형상 변화를 가능하게 하고, 제어점 위치 좌표 최적화 과정과 제어점 가중치 최적화 과정을 분리하여 단계적으로 효율적인 형상 최적화를 수행하였다. 제안한 형상최적화 방법을 예제에 적용하여 제안된 방법의 효율성을 검증하였다.

Keywords

References

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