【作者】 黄东海；

【导师】 曾志新； 李勇；

【作者基本信息】 华南理工大学 ， 机械制造及其自动化， 2010， 硕士

【摘要】 随着微电子、光电子芯片热流密度急剧增加及有效散热空间日益狭小,具有高导热率、高可靠性、热响应快、重量轻、无需额外电力驱动等特点的沟槽式微热管已成为航空及光电子领域普遍使用的理想导热元件。然而,微热管在实际应用中,往往受限于复杂多变且有限的空间,因此必须将微热管进行弯曲加工以适应不同的工作环境。由于沟槽式微热管壁薄、微小沟槽多,且弯曲加工时不能使用芯棒等特点,难以按常规管材弯管工艺进行加工。本文以分析其成形机理为基础,比较多种常用弯管工艺方式对此种工况的优劣性,并着重研究其成形缺陷,找出影响最大的缺陷,并分析其成形机理,以期消除此种缺陷,指导弯管工艺实施及其质量控制。首先比较多种弯管工艺对此种工况的优劣性,制定出最适合的弯管工艺;并以实验研究为基础,分析沟槽式微热管弯曲成形机理,以及缺陷形成规律,然后以三维的有限元弯管数值模拟对微热管弯管工艺成形进行分析研究,并以实验研究和有限元模拟为基础,尝试建立对应力学模型。指导弯管工艺实施及其质量控制。主要内容及结果如下:(1)比较和分析了常用的弯管方式:压弯、拉弯、绕弯、推弯、滚弯等,对此种特定工况的优劣性,并选出最适用的方法,并制定弯管工艺;(2)为找出对微热管性能影响最大的缺陷,并对其深入研究,以期消除此种缺陷,开发了微热管传热性能测试平台,研究弯管缺陷对传热性能的影响,并界定了所能接受的缺陷形式和程度,以及影响最大的缺陷类型;(3)进行实验研究,研究了绕弯工艺成型极限及缺陷成型规律,以及管内外壁面缺陷联系;(4)结合实验研究和三维有限元弯管数值模拟方法,对沟槽式薄壁微热管弯曲工艺的应变、应力状态、成形机理及缺陷形成规律等进行了分析;(5)通过对沟槽式薄壁微热管弯管工艺实验研究及模拟结果,应用薄板受压失稳理论,建立了微热管弯曲内侧起皱的数学模型,弥补了有限元模拟的不足;(6)为指导实际生产中工厂对弯管质量的控制与优化,根据实验研究、三维有限元方法模拟和理论分析结果,提出了弯曲工艺改进方案,实施效果良好。更多还原

【Abstract】 As the microelectronics, optoelectronics chip heat flux increase rapidly, and the space for heat dissipation growing small, power-driven grooves micro heat pipe with high thermal conductivity, high reliability, fast thermal response and no extra features has become a ideal and widely used thermal components for aviation and optoelectronics. However, the micro heat pipe limited by incapacious and complex space in practice, so it must be bended to adapt to different working environments.As the micro-grooves heat pipe has thin wall and many tiny grooves, and can not use mandril when bending it, etc, it is difficult to process by conventional tube pipe bending process. This paper analyzes the mechanism of heat pipe bending deformation, based on comparison of different methods commonly used in pipe bending on the pros and cons of such a condition. And focuses on the forming defects, identify the defects has greatest impact, and to analyze the forming mechanism in order to eliminate such defects to guide the implementation of process and the quality control of pipe bending.First of all, compare the pipe bending methods on the pros and cons of such a condition and analyze the mechanism of micro-grooved heat pipe bending deformation based on some experiments, then analysis the micro heat pipe bending process with three-dimensional finite element numerical simulation, and attempt to establish a wrinkling model based on experimental study and finite element simulation to guide the implementation and quality control of micro heat pipe bending. Main contents and results are as follows:(1) Compare and analyze the advantages and disadvantages of some common bending methods, and select the most appropriate method for such specific conditions;(2) Develop a heat transfer performance test platform for heat pipe, to study influence to the heat pipe performance of the bending defects, and defines the acceptable defects, as well as the most influential type of defect;(3) Perform the experimental study the rotary draw bending process, analyze the forming limit, the defect shaping-law, and the relationship of the defects occur on inside and outside of the wall;(4) Based on the experimental study and three-dimensional numerical simulation of bending, strain, stress state and formation mechanism of thin-walled micro-grooved heat pipe bending process are analyzed;(5) Base on the experimental study and simulation results of thin-walled micro-grooved heat pipe bending, and the thin plate buckling theory, the mathematical model of wrinkling has been founded to make up for weakness in analyzing the wrinkling of finite element simulation;(6) Proposed an improvement of heat pipe bending process, based on experimental studies, three-dimensional finite element simulation and theoretical analysis results.更多还原