单晶片振子压电泵的疲劳分析与实验研究

发布时间：2018-03-30 18:03

本文选题：单晶片　切入点：压电振子　出处：《吉林大学》2013年硕士论文

【摘要】：压电泵是利用压电效应使振子产生弯曲变形，再由变形引起密闭泵腔的容积变化来实现流体传输的一种微型泵，具有结构简单，能耗低，体积小，，精度高，无电磁干扰，易集成，易控制等诸多优点，现已广泛应用在生物医学、航空电子设备、机器人视觉、微机电工程、石化设备等各种领域。压电泵的核心部件为压电振子，压电振子通常是在循环的交变电场下连续工作，长时间工作以后，压电振子会出现裂纹萌生和扩展、疲劳断裂甚至是退极化等各种问题，严重时甚至会导致整个压电泵的疲劳失效，这会严重限制压电泵在微机电领域各个方面的广泛应用。同时，随着压电泵产品的实用化，系列化，市场化的不断发展，也急需我们明确压电泵产品的失效形式和疲劳寿命等。本文通过振子疲劳仿真分析、振子疲劳试验和压电泵加速疲劳寿命试验，分析了振子的失效模式并确定出压电泵的疲劳寿命，从而为压电泵的广泛应用打下基础。主要研究内容如下：分析了压电陶瓷的极化处理和制造工艺对其疲劳寿命的影响；分析了压电陶瓷的失效模式，主要包括机械疲劳和电疲劳。机械疲劳主要导致陶瓷的断裂破坏，而电疲劳容易引起陶瓷发生退极化或介电击穿。利用Miner线性疲劳积累损伤理论，通过ANSYS有限元软件对压电振子进行疲劳仿真分析，得到单晶片压电振子的疲劳耗用系数，确定了振子振动时长六个月内的疲劳稳定性。同时研究了不同结构参数对压电振子疲劳寿命的影响，进而对振子进行参数优选。对压电振子实施了疲劳试验，得出了电载荷、振子性能和可循环次数之间的关系，并从可靠性角度，判定其疲劳失效定级试验结果为合格。同时对比了自粘振子与进口振子的疲劳特性。通过继续给振子施加高电压循环疲劳实验，得出部分振子完全破坏的循环振动次数，根据描点法和曲线拟合，绘制出压电振子的疲劳特性曲线。对压电泵实施定数截尾恒加疲劳寿命试验，得到了PSD35型压电泵产品的特征寿命、加速系数、瞬时失效率、平均失效率、平均寿命以及可靠寿命。并求得可靠度为0.95时，PSD35型压电泵在额定电压130V（峰峰值367Vpp）下的可靠寿命为5102小时。同时分析了压电泵疲劳破坏的失效类型。其失效类型主要包括：1.压电振子损坏；2.被动截止阀片的塑性变形；3.密封圈的性能失效；4.流道堵塞。并提出相应的改进措施，主要包括振子的优良选取，工作电压的合理选择，阀片加工工艺的改进，密封圈安装的精确定位以及流体的过滤和净化处理等。
[Abstract]:Piezoelectric pump is a kind of miniature pump which can make the vibrator bend and deform by the piezoelectric effect, and then change the volume of the closed pump cavity by the deformation to realize the fluid transmission. It has simple structure, low energy consumption, small volume, high precision and no electromagnetic interference, and the piezoelectric pump has the advantages of simple structure, low energy consumption, small volume, high precision and no electromagnetic interference. It has been widely used in biomedical, avionics, robot vision, micro-electromechanical engineering, petrochemical equipment and other fields. The core component of a piezoelectric pump is a piezoelectric oscillator, which usually works continuously under a cyclic alternating electric field. After a long period of work, the piezoelectric vibrator will have crack initiation and propagation, fatigue fracture and even depolarization, and so on. At the same time, with the development of the practical, serialized and market-oriented piezoelectric pump products, the fatigue failure of the whole piezoelectric pump will seriously limit the wide application of the piezoelectric pump in the field of MEMS. There is also an urgent need for us to define the failure form and fatigue life of piezoelectric pump products. In this paper, the failure mode of the vibrator is analyzed and the fatigue life of the piezoelectric pump is determined by means of the fatigue simulation analysis of the vibrator, the fatigue test of the vibrator and the accelerated fatigue life test of the piezoelectric pump. Thus lay the foundation for the wide application of piezoelectric pump. The main research contents are as follows:. The effects of polarization treatment and manufacturing process on fatigue life of piezoelectric ceramics are analyzed, and the failure modes of piezoelectric ceramics, including mechanical fatigue and electrical fatigue, are analyzed. However, electrical fatigue can easily lead to depolarization or dielectric breakdown of ceramics. Using the Miner linear fatigue accumulation damage theory, the fatigue simulation analysis of piezoelectric vibrator is carried out by ANSYS finite element software, and the fatigue consumption coefficient of single crystal piezoelectric oscillator is obtained. The fatigue stability of the vibrator within six months is determined, and the influence of different structural parameters on the fatigue life of the piezoelectric oscillator is studied, and the parameters of the vibrator are selected. The fatigue test of piezoelectric vibrator is carried out, and the relationship among electric load, oscillator performance and cycle times is obtained, and from the point of view of reliability, The fatigue failure rating test results are determined to be satisfactory. The fatigue characteristics of the self-adhesive oscillator and the inlet oscillator are compared at the same time. By continuing to apply the high voltage cyclic fatigue test to the oscillator, the cyclic vibration times of the partial oscillator are obtained. According to the point drawing method and curve fitting, the fatigue characteristic curve of piezoelectric vibrator is drawn. The characteristic life, acceleration coefficient, instantaneous failure rate and average failure rate of PSD35 piezoelectric pump are obtained by means of the constant fatigue life test of the pressure-electric pump. The average life and reliable life of PSD35 piezoelectric pump with reliability of 0.95 are obtained, and the reliable life of PSD35 piezoelectric pump is 5102 hours under rated voltage of 130 V (peak value 367 Vpp.). At the same time, the failure types of piezoelectric pump fatigue failure are analyzed. The failure types mainly include: 1. Piezoelectric vibrator damage. 2. Plastic deformation of passive stop valve. 3. Performance failure of sealing ring. 4. Flow channel clogging. Corresponding improvement measures are put forward. It mainly includes the excellent selection of the vibrator, the reasonable selection of the working voltage, the improvement of the processing technology of the valve plate, the precise location of the sealing ring installation, the filtration and purification of the fluid, etc.
【学位授予单位】：吉林大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：TH38

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