프랙탈 차원을 이용한 재료손상의 자기 상사성에 관한 연구 = A Study on Self-similarity of Material Damage using Fractal Dimension

다국어 초록 (Multilingual Abstract)

The postion and the length of surface micro-crack has random properties. It is difficult to detect the progressive changes in surface micro-crack distribution that occur during fatigue stressing. In this paper to overcome this problem, fractal dimension was introduced to characterized the change in two-dimensional surface micro-crack distribution during fatigue process. Box counting method was adopted to measure the fractal dimension. The features of surface micro-crack growth and coalescence have fractal property. Fractal dimension increases with the number of cyclic load. Remaining fatigue life of mechanical components can be predicted by the relation between fractal dimension and cycle ratio to fracture. Therefore, we proposed complex system design that uses fractal dimension in material design and structure design and safety estimation.

목차 (Table of Contents)

• 1. 서론
• 2. 실험방법
• 2.1 실험재료 및 시험편
• 2.2 피로와 프랙탈 해석 실험
• 3. 프랙탈치 정의와 측정
• 3.1 프랙탈 차원의 정의
• 3.2 박스계수법을 이용한 프랙탈 차원의 측정
• 4. 실험 결과 및 고찰
• 4.1 프랙탈 해석
• 4.2 프랙탈 차원 D_f를 이용한 잔존수명평가
• 5. 결론