共查询到19条相似文献,搜索用时 234 毫秒
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基于斯特林制冷机用动圈式直线压缩机及其相应简化物理模型,给出了振子的受力特性和振子系统动力学控制方程,通过对动圈式直线压缩机的性能仿真系统的就其共振频率及特性进行了分析,对整机优化设计与性能改进具有重要意义。 相似文献
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由弯振辐射阶梯盘与纵振换能器组合而成的复合超声振动系统,因其兼具弯曲振动低声阻抗和纵振换能器高辐射效率的特点,在气介式功率超声领域有着很好的应用。阶梯圆盘的频率方程中包含特殊函数,且方程数目多,求解过程非常繁杂。以自由边界条件下的单阶梯、双阶梯弯振圆盘为例,提出在给定阶梯圆盘弯振频率﹑基底厚度以及材料参数的条件下利用数值计算方法,编程设计阶梯圆盘的方法。试验测试与理论计算相吻合。为多阶梯弯振圆盘的设计提供一种新的方法。 相似文献
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N. G. Leshchenko V. F. Muzhitskii V. B. Remezov 《Russian Journal of Nondestructive Testing》2005,41(7):421-429
The dependence of the displacement on the depth and width of the working clearance during acoustic (ultrasonic) wave excitation under the action of the Lorentz force developed by single-wire vibrator is considered. Unlike in studies performed earlier, the plane perpendicular to the axis of the vibrator is presented. Theoretical and calculated data are compared. The design of an electromagneticacoustic (EMA) transducer is described. An instrument based on a similar transducer was approved at a number of enterprises. 相似文献
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超低频标准振动台支承弹簧选择设计 总被引:1,自引:1,他引:0
通过实验的方法研究了乳胶管弹簧在不同的并联股数、初始长度及规格组合下的力 -位移特性 ,并运用最小二乘原理给出了拟合曲线方程。同时求解了采用该乳胶管弹簧下的超低频标准振动台的运动方程近似解 ,得到了波形失真度计算式。最后计算了不同组合下弹簧的波形失真度 ,为设计超低频标准振动台波形失真度最小的支承弹簧提供了选择依据 相似文献
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A driving circuit of frequency adapting for an ultrasonic vibrator with motional current feedback has been presented in this paper. Via a voltage-controlled oscillator (VCO) and a digital/analog converter (DAC), the driving signal would be magnified by a linear power amplifier to actuate the vibrator. Since the vibrating velocities or displacements at the surface end of a vibrator could be predicted through the measurement of motional current, the motional current passing through the vibrator was detected by a current transformer (CT) type sensor as feedback to monitor the optimal level of output power. The calculation for phase difference and the tuning strategy for driving frequency were implemented by a microcontroller integrated with an A/D converter and a voltage comparator as well as the signal attenuation and level tuning circuit. The experiment demonstrates that the temperature effect corresponding to frequencies is at 9.75 Hz/°C shifting and the external loading reflected to frequencies is about 8.3 Hz/gm offset. The proposed circuit has the great performance in rejecting the disturbances from external loading and thermal effect. 相似文献
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介绍了小型扭杆弹簧倾斜仪的工作原理,使用ANSYS有限元分析软件对扭杆弹簧振子进行了静态、模态等分析,给出了应力云图和各阶振型图。从理论和实验方面研究了扭杆弹簧振子的固有频率,结果表明,实验测试与理论估算值同ANSYS分析值大体吻合。分析了倾斜仪的灵敏度与电容传感电路的灵敏度、扭杆弹簧振子几何尺寸等之间的关系,提出了一种新的振子弹性结构,有限元分析结果表明:此结构有利于提高倾斜仪的机械灵敏度,减少交叉耦合误差,增加了仪器机械本体的稳定性。 相似文献
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在以弦向声道布置的多声道超声气体流量计原理的基础上,采用Gauss-Legendre数值积分和线性神经网络相结合的方法完成自适应调整权系数的多声道超声气体流量计建模。在建模过程中,根据Legendre正交多项式的节点值,计算多声道超声换能器的位置分布值,再按照Widrow-Hoff学习规则,由leanrwh函数求解出各声道的层流流速和权系数值表,最后根据实时测量出的层流流速,通过插值算法自适应匹配一组最佳的权系数值,计算出流速和流量值。并以4声道交叉布置方式的超声气体流量计为例,进行测量误差仿真实验和物理实验,误差均能满足实际测量要求。 相似文献
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通过模仿蝗虫起跳过程中的后足胫节末端的直线运动轨迹和起跳稳定性,提出了一种仿蝗虫八杆跳跃机器人设计方法。建立运动学模型并利用天牛须搜索算法对机构的尺寸参数进行优化设计,优化后的八杆跳跃机构的等效胫节末端轨迹和蝗虫后足胫节起跳过程的末端轨迹吻合,基本为一条斜直线。基于拉格朗日方程对八杆跳跃机构的起跳动力学进行建模,并分析了身体所在杆的质心位置对起跳过程的影响,发现通过增大等效跗节杆的质量能提高起跳动力学稳定性。根据运动学和动力学分析的结果,设计了仿蝗虫八杆跳跃机器人,并利用高速摄像机搭建实验平台记录其起跳过程,验证了等效跗节杆的质量对起跳动力学稳定性具备有效的调节效果。 相似文献
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The Doppler modulation system is a principal part of a Mössbauer spectrometer. It includes the Doppler modulator (velocity transducer) and a control system (the modulator driver) which consists of a function generator that produces a reference signal by which the vibrator can be controlled and the error correction circuit that corrects the motion of the vibrator according to the reference signal. The motion of the driver must be identical to the preferred wave shape for the operation of the spectrometer. The aim of the present article is to design and test a low cost lab-built modulator velocity driver for a Mössbauer spectrometer to be used in the constant acceleration (triangular) mode of operation, although it can be used in the other operational modes. A triangular wave is stored in RAM. The axis of the vibrator carries two coils, one for the driving signal and the other for the pickup signal which gives the shape of the motion of the driver (i.e., the actual motion of the source). The stored reference triangular wave is compared with the one from the pickup coil and the difference between them gives an error signal. The error signal will be zero if the motion of the vibrator is identical to that of the stored wave. This error signal is added to the driving pulse in a suitable phase and amplitude in order to obtain a source motion with minimized deviation from its correct value. 相似文献
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从变截面杆作一维纵振动的运动方程出发,建立机械四端网络的数学模型及传输特性方程,导出了超声珩齿复合振动系统的频率方程和放大系数计算公式。将小端接圆柱杆的复合圆锥形变幅杆与被加工齿轮组成复合振动系统,将齿轮简化为圆柱杆,采用四端网络方法,得出了复合振动系统的频率方程与放大系数公式。 相似文献