【作者】 翁玲；

【导师】 王博文；

【作者基本信息】 河北工业大学 ， 电工理论与新技术， 2008， 博士

【摘要】 超磁致伸缩材料Terfenol-D具有逆磁致伸缩效应,利用这种效应可以制作超磁致伸缩振动传感器。基于逆磁致伸缩效应的振动传感技术,很有可能开发出新一代的振动传感器,它可广泛应用于振动测试和主动振动控制领域,促进振动测试与振动控制技术的发展。本文选择了“超磁致伸缩振动传感器的模型与实验研究”这一既具有科学价值又具有工程实际意义的课题,以期对超磁致伸缩振动传感器的开发及应用提供支持。本文的主要工作如下:1、研究了振动传感器中的核心元件Terfenol-D在一定的偏置磁场下外压应力和应变的关系,结果表明当给Terfenol-D棒施加轴向偏置磁场时,应力与应变之间呈现复杂的非线性关系。由此关系引出杨氏模量随磁场的变化及ΔE效应,从磁性材料磁畴理论和磁导率入手,解释了偏置磁场下应力和应变的关系。进行了一定偏置磁场下外应力和磁感应强度的实验研究,实验结果表明偏置磁场为5kA/m时,磁感应强度最大。2、在Jiles-Atherton模型、电磁学原理和换能器系统的结构动力学原理的基础上,考虑交流驱动电流和动态应力的变化,建立了外加交流磁场和动态应力共同作用下的超磁致伸缩换能器的动态模型,利用该模型计算了描述动态磁场和动态应力共同作用下的换能器输出位移、输出力和感应线圈两端产生的感应电压的变化规律。3、当给换能器施加的磁场为驱动场,应力为常应力,换能器以致动器模式工作,利用上述模型计算了超磁致伸缩致动器的输入电流和输出应变(或位移),并进行了实验测试,计算结果和实验结果符合较好;当外加应力为动态应力,磁场为常量时,换能器以传感器模式工作,上述模型可用于确定磁致伸缩传感器的感应电压。4、进行了振动传感器的实验研究,确定传感器感应电压峰-峰值和传感器的驱动条件及偏置条件(偏置磁场和预应力)的关系,并把实验结果和理论计算值进行了对比,结果基本相符。采用平均法和五点三次平滑法对部分实验数据进行了平滑预处理,处理后采用傅立叶变换进行数字带通滤波,消除了白噪声。5、根据振动传感器的机电变换原理,结合惯性传感器的机械接收原理,建立了超磁致伸缩振动传感器的传递函数模型,该模型可以描述振动传感器的输出电压和输入振动信号的变化关系。进行了振动传感器的时域分析、频域分析和灵敏度分析。基于零极点配置的原理进行了振动传感器的低频特性补偿的仿真研究,为振动传感器的低频特性补偿提供了参数。更多还原

【Abstract】 The giant magnetostrictive material Terfenol-D has a reverse magnetostrictive effect, and a magnetostrictive vibration sensor can be designed based on this effect. The vibration sensing technology, based on the reverse magnetostrictive effect, possibly develop a new vibration sensor to be widely used in vibration testing and vibration control, which would speed up the development in vibration testing and controlling. To provide the groundwork of the optimizing design and application of the magnetostrictive vibration sensor, the model and experiment of the sensor are selected as the subject of dissertation for Ph.D. The main research work is following:1. The relationship between strain and compressive stress under different bias magnetic fields of the core element Terfenol-D in magnetostricitve vibration sensor is researched. The results show that the relationship between them is complex and nonlinear when the longitudinal bias magnetic field acts on Terfenol-D, the Young’s modulus dependence of the magnetic fields andΔE effect are acquired from the relationship between strain and stress. The curve of strain and stress under variable bias magnetic fields is explained through magnetic domain theory and magnetic permeability. The experiments of the stress and magnetic induction under different bias magnetic fields are carried out, the results show that the magnetic induction is maximal when the bias magnetic field is 5kA/m.2. A model of giant magnetostrictive transducer under AC driving magnetic fields and dynamic stress is presented, based on the Jiles-Atherton model, the magnetic principle and the transducer’s structural dynamics principle. The output displacement, output force and the sensing voltage of the sensing coils are computed when the transducer is under both AC driving magnetic fields and dynamic stress.3. When the magnetic field is AC driving field and the stress is constant, the transducer works as an actuator, then the above mentioned model can be used to compute the relationship between the output displacement and the input current. The experiments of the transducer are processed, and it is found that the computing results and experimental ones are coincident on the whole. When the stress is dynamic and the magnetic field is constant, the transducer works as a sensor, and the above mentioned model can be used to compute the sensing voltage of the sensor.4. An experimental study on the sensing voltage of the sensor is carried out to determine the relationship between the peak to peak value of the voltage and the driving force as well as the bias magnetic field. Experimental data are in a good agreement with computing results. Some experimental data are processed beforehand with averaging method and five points-thrice smoothing technique, then they are filtered with Fourier transformation, and the white noise is eliminated.5. The transfer function of the magnetostrictive vibration sensor is founded based on the electromechanical transform theory of Terfenol-D and mechanical accepting theory of inertial sensor, the model can describe the change of sensor’s output voltage and input vibration. The time domain analysis, frequency domain analysis, and sensitivity analysis of the sensor are finished in the paper. The simulation of low frequency compensation is processed based on zero -pole configuration theory, and the parameter is useful to low frequency compensation of the sensor.更多还原