• Title/Summary/Keyword: thermal modeling

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Improved Modeling of the Effects of Thermal Residual Stresses on Single Fiber Pull-Out Problem

  • Chai, Young-Suk;Park, Byung-Sun;Yang, Kyung-Jun
    • Journal of Mechanical Science and Technology
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    • v.15 no.7
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    • pp.823-830
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    • 2001
  • The single fiber pull-out technique has been commonly used to characterize the mechanical behavior of fiber/matrix interface in fiber reinforced composite materials. In this study, an improved analysis considering the effect of thermal residual stresses in both radial and axial directions is developed for the single fiber pull-out test. It is found to have the pronounced effects on the stress transfer properties across the interface and the interfacial debonding behavior.

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Study on the Thermal and Dynamic Behaviors of Air Spring for vibration isolation of LCD panel inspecting machine connected with an External Chamber through a flexible tube: PART I, Theoretical Modeling (외부챔버와 유연한 튜브로 연결된 LCD 패널 검사기 방진용 공기 스프링의 열 및 동적 연성거동에 대한 연구: PART I, 이론적 모델링)

  • Seok, Jong-Won;Lee, Ju-Hong;Kim, Pil-Kee
    • Journal of the Semiconductor & Display Technology
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    • v.10 no.1
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    • pp.33-41
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    • 2011
  • Due to the recent quantum leaps forward in bio-, nano-, and information-technologies (BT, NT and IT), the precisionization and miniaturization of mechanical and electrical components are in high demand. In particular, the ITrelated equipments that take a great part in our domestic industry are in the area requiring high precision technologies. As a consequence, the researches on the development vibration isolation systems that diminish external disturbance or internal vibration are highly required. Among the components comprising the vibration isolation system, air spring has become on a focal point for the researchers due to its merits. This air spring is able to support heavy loads, keep a low natural frequency despite of having a lower value of stiffness, and control the performance of vibration isolation. However, sometimes the sole use of air spring is in demand due to some economic reasons. Under this circumstance, the damping effect of sole air spring may not enough to reduce sufficient amount of vibration. In this study, the air spring mount system connecting with an external chamber is proposed to increase or control the damping effect. To investigate its damping mechanism, the thermal and dynamic behaviors of the system is examined through a theoretical modeling approach in this part of research. In this approach, thermomechanical and Helmholtz resonator type models are to be employed for the air spring/external chambers and connecting tube system, respectively. The frequency response functions (FRFs) derived from the modeling effort are evaluated with physical parametric values and the effects of connecting tube length on these FRFs are identified through computer simulations.

A study on the OMM error compensation considering the thermally induced errors (열변형 오차를 고려한 기상측정 오차 보정에 관한 연구)

  • 박규백;송길홍;조명우;권혁동;서태일
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2002.05a
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    • pp.399-404
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    • 2002
  • Improvement of measuring accuracy is an essential part of quality control manufacturing process. The OMM is less than the CMM in measure accuracy but the OMM system is more efficient, easier to use than other measurement system. About 40~70% of the machine tool errors are induced by the thermal errors. Therefore, a key requirement for improving the measuring accuracy is to reduce the geometric and thermal errors. Thermal errors are measured by a ball bar system and predicted by the thermal error modeling. Furthermore, using the pre-defined thermal error map approach compensates the geometric accuracy of the OMM. Appropriate experiments are performed using ball-bar system, temperature measuring devices and touch-type probe. Compensated results are compared with those obtained using CMM to verify the proposed methods.

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Thermal Resistance Modeling of Linear Motor Driven Stages for Chip Mounter Applications (칩 마운터용 리니어 모터 스테이지의 열저항 모델링)

  • Jang, Chang-Su;Kim, Jong-Yeong;Kim, Yeong-Jun
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.26 no.5
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    • pp.716-723
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    • 2002
  • Heat transfer in linear motor driven stages for surface mounting device applications was investigated. A simple one-dimensional thermal resistance model (TRM) was introduced. In order to reduce three-dimensional nature to one-dimensional, a few assumptions and simplifications were employed suitably. A good agreement with a finite element heat transfer analysis in temperature profile was obtained. For validation, the analysis was compared with the measurement with respect to motor driving power. Overall discrepancy was less than 7$^{\circ}C$. The influence of two high thermal resistance parts, insulation sheet and thermal contact between the coil assembly and the mounting plate, was examined through the analysis. Additionally, the thermal resistance analysis was applied to another stage including an internal cooling-air passage, and was found available for this system as well. After validation, the cooling effect was surveyed in terms of motor power, and cooling-air and -water flow rate.

Thermal Resistance Modeling of Linear Motor Driven Stages for Chip Mounter Applications (칩 마운터용 리니어 모터 스테이지의 열저항 모델링)

  • Jang, Chang-Soo;Kim, Jong-Young;Kim, Yung-Joon
    • Proceedings of the KSME Conference
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    • 2001.11b
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    • pp.96-101
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    • 2001
  • Heat transfer in linear motor driven stages for surface mounting device applications was investigated. A simple one-dimensional thermal resistance model was introduced. In order to reduce three-dimensional nature to one-dimensional, a few assumptions and simplifications were employed suitably. A good agreement with a finite element heat transfer analysis in temperature profile was obtained. For validation, the analysis was compared with the measurement with respect to motor driving power. Overall discrepancy was less than $7^{\circ}C$. The influence of two high thermal resistance parts, insulation sheet and thermal contact between the coil assembly and the mounting plate, was examined through the analysis. Additionally, the thermal resistance analysis was applied to another stage including an internal cooling-air passage, and was found available for this system as well. After validation, the cooling effect was surveyed in terms of motor power, and cooling-air flow rate.

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The thermal conductivity analysis of the SOI/SOS LIGBT structure (Latch up 전후의 SOI(SOS) LIGBT 구조에서의 열전도 특성 분석)

  • Kim, Je-Yoon;Kim, Jae-Wook;Sung, Man-Young
    • 한국컴퓨터산업교육학회:학술대회논문집
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    • 2003.11a
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    • pp.79-82
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    • 2003
  • The electrothermal simulation of high voltage LIGBT(Lateral Insulated Gate Bipolar Transistor) in thin Silicon on insulator (SOI) and Silicon on sapphire (SOS) for thermal conductivity and sink is performed by means of MEDICI. The finite element simulations demonstrate that the thermal conductivity of the buried oxide is an important parameter for the modeling of the thermal behavior of silicon-on-insulator (SOI) devices. In this paper, using for SOI LIGBT, we simulated electrothermal for device that insulator layer with $SiO_2$ and $Al_2O_3$ at before and after latch up to measured the thermal conductivity and temperature distribution of whole device and verified that SOI LIGBT with $Al_2O_3$ insulator had good thermal conductivity and reliability.

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A Study on Heat Transfer of an Induction Motor with Cooling Channels under Transient Operation Condition (냉각채널을 지닌 유도전동기의 비정상상태 운전시 열전달)

  • Lee, Jeong-Ho;Park, Sung-Hoon;Kauh, S.-Ken
    • Proceedings of the KSME Conference
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    • 2000.04b
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    • pp.205-212
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    • 2000
  • Induction motors. having axial cooling channels in stator and rotor are designed for better cooling performance. Traction motors are one of those examples. And, thermal analysis gain more attention with the Increased demand of the motors, for reliable operation and life prolongation. was Induced to effective thermal conductivity through modeling. Through. fundamental comparison experiment, heat source experiment and transient state experiment, the induction motor using inverter was examined to produce heat source with frequency level and traced to thermal variation at starting and stopping. And thermal analysis using thermal network was compared with a transient state experiment.

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