랜덤 진동을 이용한 하드 디스크 드라이브 슬라이더 공기 베어링의 모드 해석 = (A) Modal Analysis for Slider Air-Bearing in Hard Disk Drives by Using Random Vibration

다국어 초록 (Multilingual Abstract)

In recent years, the flying height of HDD slider is significantly decreased to maximize the recording density. It has become important to know the dynamic characteristics of HDD slider air bearing in various aspects. In this paper, we investigate the dynamic behavior of the sllder air beanng by numerical simulation. The simulator used in this study employs the factored implicit finite difference scheme to solve the Reynolds equation and uses a suitable slip model at the wall condition to account for a large Knudsen number.
We apply randomly generated disk vibration and surface profile to the dynamic siumulator and get the response of the slider air bearing caused by these random excitation. There are three slider air bearing modes which are close to pitch, roll and vertical displacement modes. However, these three mode are coupled together and not easy to figure out their own effects. Therefore, we use a modal analysis technique to decouple each modes and get the mode shapes. We use circle fitting method based on the single degree of freedom.

목차 (Table of Contents)

• 목차 = ⅶ
• Abstract = ⅲ
• 기호설명 = ⅴ
• Ⅰ. 서론 = 1
• Ⅱ. 공기베어링 계산 = 5
• 1. 연속방정식 = 5
• 2. 내비어-스토크스 방정식 = 5
• 3. 1차, 2차 슬립조건 = 6
• 4. Fukui-Kaneko 모델 = 7
• 5. 일반화된 레이놀즈 방정식 = 8
• 6. FIFD(Factored Implicit Finite Diffefence)기법 = 11
• Ⅲ. 랜덤진동(Random Vibration) = 12
• 1. 랜덤변수(Random Variables) = 12
• 2. 정상랜덤과정(Stationary Random Process) = 13
• 3. 상관함수(Correlation Funtion) = 14
• 4. 파워 스패트럼 밀도(Power Spectral Density) = 15
• 5. 랜범진동의 특징 = 16
• Ⅳ. 모드해석(Modal Analysis) = 18
• 1. 주파수응답함수(Frequency Response Function) = 18
• 2. 동심원 핏팅(Circle fitting) = 18
• 3. 최소제곱법(Least Square Method) = 20
• 4. 감쇠비(Damping Ration) = 21
• 5. 모드상수(Model Constant) = 23
• Ⅴ. 수치해석 결과 = 24
• 1. 슬라이더 = 24
• 2. 입력 = 25
• 3. 응답 = 26
• 4. 디스크 진동에 대한 주파수응답함수 = 26
• 5. 주파수응답함수에 의한 동심원 핏팅 = 29
• Ⅵ. 결론 = 39
• 참고문헌 = 40