排序方式: 共有59条查询结果,搜索用时 484 毫秒
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用一个双层板结构模型采简化典型的表面波谐振器单元,并用三维弹性力学方程采精确分析在其中传播的表面波.与此同时,用O(H)近似方法对有电极的弹性板模型做了近似计算,发现在电极层厚度很小的时候,分析精度相当好.这种近似方法能减少一半的计算量,为分析复杂的模型提供了很好的近似分析方法. 相似文献
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提出并制备了一种基于聚二甲基硅氧烷(PDMS)膜封装空芯光纤的级联双腔温度传感器。该传感器由空气腔(FP1)和PDMS腔(FP2)级联而成,且PDMS腔长度远小于空气腔长度,从而使该传感器满足游标效应产生条件[FP1腔与复合腔FP3(由FP1和FP2组成)的光程接近]。当外界温度变化时,PDMS膜向两侧膨胀,导致FP1腔和FP3腔的干涉谱向相反的方向移动。实验结果表明,FP1腔和FP3腔干涉谱产生了游标效应,干涉谱包络明显;在50~60℃范围内,温度灵敏度达到1.32 nm/℃,该结果与理论分析结果相符。该传感器具有体积小、结构轻、灵敏度高、制备简单等优点,在化学、生物、医疗等领域具有潜在的应用价值。 相似文献
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该文对横向电场激励下的(yxl)-58°LiNbO_3压电谐振器的高频振动进行了研究。首先,基于Mindlin一阶板理论,计算了压电谐振器的模态频谱关系,得到晶体基板长厚比;然后,利用有限元分析软件COMSOL Multiphysics建立了谐振器的三维有限元模型,通过增加厚度方向网格扫掠层数的方法,验证了仿真模型的网格无关性;其次,通过特征频率计算与频域计算得到了谐振器一阶厚度剪切模态频率值;最后,通过改变电极与晶体板质量比以及电极间距的大小,获得了不同尺寸参数对谐振器高频振动特性的影响规律。仿真分析结果表明,电极与晶体板的质量比同谐振器谐振频率成负相关,质量比越大,谐振频率越小;电极间距值与谐振频率成负相关,间距值越大,谐振频率越小。 相似文献
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The nonlinear behaviors of a circular-cylinder piezoelectric power harvester (CCPPH) near resonance are analyzed based on the flow-induced flexural vibration mode. The geometrically-nonlinear effect of the cylinder is studied with considering the in-plane extension incidental to the large defection. The boundary electric charges generated from two deformation modes, flexure and in-plane extension, were distinguished with each other because the charge corresponding to the latter mode produces no contribution to the output current. Numerical results on output powers show that there are multi- valuedness and jump behaviors. 相似文献
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We study the effects of couplings to flexure and face-shear modes on the admittance of an AT-cut quartz plate thickness-shear mode resonator. Mindlin’s two-dimensional equations for piezoelectric plates are employed. Electrically forced vibration solutions are obtained for three cases: pure thickness-shear mode alone; two coupled modes of thickness shear and flexure; and three coupled modes of thickness shear, flexure, and face shear. Admittance is calculated and its dependence on the driving frequency and the length/thickness ratio of the resonator is examined. Results show that near the thickness-shear resonance, admittance assumes maxima, and that for certain values of the length/thickness ratio, the coupling to flexure causes severe admittance drops, while the coupling to the face-shear mode causes additional admittance changes that were previously unknown and hence are not considered in current resonator design practice. 相似文献
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