电热驱动器热—力耦合特性研究

发布时间：2018-05-12 10:31

  本文选题：电热驱动器 + 材料温度相关性　； 参考：《中国地质大学(北京)》2017年硕士论文

【摘要】：基于微机电系统(MEMS)的电热驱动器可以产生数十毫牛的力和很小微米的位移。电热驱动器具有多对V型梁和一个中央板子,在V型梁两端施加电势差,V型梁会有电流通过,由电流产生焦耳热量,热量使电热驱动器温度升高以及诱导热膨胀,使中央板子产生向前的驱动位移和拉力。研究电热驱动器的热-力耦合模型以及热-位移耦合模型。电热驱动器的制作材料采用多晶硅,多晶硅的材料特性是温度相关的,在电热驱动器热-力耦合模型、热-位移耦合模型中考虑到了温度相关的材料特性。电热驱动器V型梁结构的力学反应,通过V型梁结构的一半单一斜梁能够同等地计算出来。建立关于电热驱动器关键单元斜梁的三种理论模型:简支梁模型、定向铰支座模型、固定端模型。温度相关材料性对斜梁临界支反力、轴向内力,以及温度相关材料特性对斜梁随温度升高产生位移是本质重要的。温度相关材料特性对电热驱动器最大允许施加电势差、温度分布云图、位移分布云图是极为重要的。随着纳米科技的发展,当斜梁的尺寸变成纳米级别时,尺寸效应对于杨氏模量、热膨胀系数的影响变得重要起来。尺寸效应对于纳米斜梁力学表现,如临界支反力、温度升高产生的支反力是极为重要的。
[Abstract]:Electrothermal actuators based on MEMS (MEMS) can produce tens of millibull force and very small micron displacement. The electric heat driver has many pairs of V-shaped beams and a central plate. When the potential difference between the two ends of the V-shaped beam is applied, the V-shaped beam will have an electric current passing through, resulting in joule heat produced by the current, and the heat will increase the temperature of the electrothermal actuator and induce thermal expansion. Causes the central plate to produce the forward drive displacement and the pull force. The thermal-mechanical coupling model and thermal-displacement coupling model of electrothermal actuator are studied. The material of electrothermal actuator is made of polycrystalline silicon, and the material characteristic of polysilicon is temperature-dependent. The thermal-mechanical coupling model and thermal-displacement coupling model of electrothermal actuator are used to consider the temperature-dependent material characteristics. The mechanical response of V-beam structure with electrothermal actuator can be calculated equally by half of the single skew beam of V-beam structure. Three kinds of theoretical models of oblique beam with key elements of electrothermal actuator are established: simply supported beam model, directional hinge support model and fixed end model. The critical supporting reaction force axial internal force and temperature-related material properties of temperature dependent material are essential to the displacement of oblique beam with the increase of temperature. The properties of temperature-dependent materials are of great importance to the maximum allowable potential difference, temperature distribution, and displacement distribution of the electrothermal actuator. With the development of nanotechnology, the effect of size effect on Young's modulus and coefficient of thermal expansion becomes important when the size of oblique beam changes to nanometer level. The size effect is very important for the mechanical behavior of nanometer skew beam, such as the critical branch reaction force and the branch reaction force caused by the increase of temperature.
【学位授予单位】：中国地质大学(北京)
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TH-39
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本文编号：1878267