共查询到20条相似文献，搜索用时 359 毫秒
1.
通过对反卷积的理论推导的介绍,实现对光纤光栅传感器Bragg波长移动的法布里一珀罗（F—P）腔解调精度的分析。把从F—P腔解调出来的、分辨率降低的光功率谱经过已知传感光栅的光功率谱进行反卷积运算,得到一个与被测光纤光栅光功率谱更为接近的光功率谱,使得被测信号得以恢复,从而提高光纤光栅波长位移测量精度。 相似文献
2.
大型工程如坡体滑移、地基沉降等的变化都属于位移较大的移动。因此根据OTDR的弯曲损耗测试原理,设计了一种基于此原理的组合式光纤传感器,该传感器可以根据实际位移变化的需要改变量程的大小,并对单个该传感器进行了理论推导和试验测试,得出拟合公式。该实验结果可为弯曲损耗位移光纤传感器的开发研究作参考。 相似文献
3.
This paper discusses the validity of (adaptive) Lagrange generalized plain finite element method (FEM) and plate element method
for accurate analysis of acoustic waves in multi-layered piezoelectric structures with tiny interfaces between metal electrodes
and surface mounted piezoelectric substrates. We have come to conclusion that the quantitative relationships between the acoustic
and electric fields in a piezoelectric structure can be accurately determined through the proposed finite element methods.
The higher-order Lagrange FEM proposed for dynamic piezoelectric computation is proved to be very accurate (prescribed relative
error 0.02%–0.04%) and a great improvement in convergence accuracy over the higher order Mindlin plate element method for
piezoelectric structural analysis due to the assumptions and corrections in the plate theories. The converged Lagrange finite
element methods are compared with the plate element methods and the computed results are in good agreement with available
exact and experimental data. The adaptive Lagrange finite element methods and a new FEA computer program developed for macro-
and micro-scale analyses are reviewed, and recently extended with great potential to high-precision nano-scale analysis in
this paper and the similarities between piezoelectric and seismic wave propagations in layered structures and plates are stressed.
Project supported by SRF for ROCS, SEM of China and partially by Zhejiang Provincial Natural Science Foundation (NSF) of China. 相似文献
4.
An analytical sandwich beam model for piezoelectric bender elements is derived based on the first-order shear deformation theory （FSDT）, which assumes a single rotation angle for the whole cross-section and a quadratic distribution for coupled electric potential in piezoelectric layers. Shear coefficient is introduced to correct the effect of transverse shear strain on shear force and the electric displacement integration. Static and free vibration analyses of simply-supported bender elements are carried out for the sensor function. The results illustrate the high accuracy of the present model compared with the exact 2D solutions. 相似文献
5.
基于ANSYS的应力分析功能进行压力传感器特性研究,用ANSYS数值计算方法分析了压力传感器的弹性平行梁。数值计算结果表明,压力传感器的节点位移与压力之间存在线性关系,说明在一定范围内,输出电压与被测物体的重量成正比,和实验结果一致。计算机仿真手段能够得到直观弹性平行梁应力云图,更可以用动画生动的应力作用实验过程和结果。一定程度上弥补了实验教学手段的不足,展示普通实验无法完成的实验内容,还可以清楚地知道电阻应变片应该固定的具体位置。 相似文献
6.
Parameters optimization and nonlinearity analysis of grating eddy current displacement sensor using neural network and genetic algorithm 总被引：1，自引：0，他引：1
A grating eddy current displacement sensor （GECDS） can be used in a watertight electronic transducer to realize long range displacement or position measurement with high accuracy in difficult industry conditions. The parameters optimization of the sensor is essential for economic and efficient production. This paper proposes a method to combine an artificial neural network （ANN） and a genetic algorithm （GA） for the sensor parameters optimization. A neural network model is developed to map the complex relationship between design parameters and the nonlinearity error of the GECDS, and then a GA is used in the optimization process to determine the design parameter values, resulting in a desired minimal nonlinearity error of about 0.11%. The calculated nonlinearity error is 0.25%. These results show that the proposed method performs well for the parameters optimization of the GECDS. 相似文献
7.
8.
针对传统的强度型光纤位移传感器安装复杂、漂移大等问题,采用光纤光栅新型位移传感器,设计并实现了一种波长编码、自校准和不受光强影响的新型光纤光栅位移传感实验装置。该实验装置简化了传统强度编码光纤传感器的安装过程,具有抗环境振动和温度补偿功能,对快速掌握新型光纤光栅位移传感原理和使用方法,提高光纤传感实用技能具有实际的意义。 相似文献
9.
贾群 《淮南师范学院学报》2012,14(3):14-16
通过对光纤位移传感器进行动态系统测试,并由实验数据进行相应的系统辨识和补偿,通过脉冲响应梯度校正模型和滤波器设计确定较为合适的系统模型,达到了较好的系统辨识效果。 相似文献
10.
We developed a measuring instrument that had wide range, high precision, small measuring touch force. The instrument for three-dimensional （3D） surface topography measurement was composed of a high precision displacement sensor based on the Michelson interference principle, a 3D platform based on vertical scanning, a measuring and control circuit, and an industrial control computer. It was a closed loop control system, which changed the traditional moving stylus scanning style into a moving platform scanning style. When the workpiece was measured, the lever of the displacement sensor returned to the balanced position in every sample interval according to the zero offset of the displacement sensor. The non-linear error caused by the rotation of the lever was, therefore, very small even if the measuring range was wide. The instrument can measure the roughness and the profile size of a curved surface. 相似文献
11.
为了研究不同频率的激振力叠加作用下平板叶片的位移响应变化,在平板叶片上选取激励点和多个响应点进行相关性激励试验。试验中,首先运用设计的加法器对频率为112、280和583 Hz的简谐力分别进行叠加,然后以压电陶瓷片作为激振器对平板叶片进行激励,同时以压电陶瓷片作为感应器采集位移响应,最后应用谱分析方法对位移响应进行分析。通过对比不同频率的激振力叠加作用下的位移响应自功率谱幅值,发现自功率谱幅值比单一频率激振力作用时有所降低,并且降低的程度和与其叠加的激振力频率的大小和个数有关,叠加的个数越多,降低的程度越大。 相似文献
12.
A closed-form out-of-plane dynamic displacement response of a curved track subjected to moving loads was pro- posed. The track structure was modeled as a planar curved Timoshenko beam periodically supported by the double-layer spring-damping elements. The general dynamic displacement response induced by the moving loads along the curve on the elastic semi-infinite space was firstly obtained in the frequency domain, according to the Duhamel integral and the dynamic reciprocity theorem. In the case of the periodic curved track structure subjected to moving loads, the dynamic displacement equation was simplified into a form of summation within the basic track cell instead of the integral. The transfer function for the curved track was expressed in the form of a transfer matrix. Single and series moving loads were involved in the calculation program. For the verification of the analytical model, the mid-span vertical deflection of a simply support curved beam subjected to moving load was recalculated and compared with the same case in the reference. The research results indicate that： under the same moving loads, the displacement response of the curved track decreases slightly with the increasing track radius, and the displacement response of the curved track with the radius greater than or equal to 600 m is almost equivalent to the displacement response of the straight track; the frequency spectrum of the curved track is more abundant than that of the straight track, which may result in more wheel-rail resonance and rail corrugation in the curved lines. 相似文献
13.
The grating eddy current displacement sensor （GECDS） for distance or position measurement used in watertight electronic calipers was described. The sensor relies on repetitive variation of inductance against displacement caused by the change of coupling areas between moving coils and static reflectors. The investigations focused on setting up and utilizing a computer model of the 3D eddy current fields and geometry to analyze causes of the production of measurement blind areas, and to investigate effects of the sensor parameters, such as axial gap between coils and reflectors, reflector length and reflector width on characteristics of the sensor. Simulation results indicated that the sensor has the smallest nonlinearity error of 0.15%, which agrees well with the experimental results. 相似文献
14.
A novel cement matrix smart piezoelectric composite and its application as sensing element are presented. A cement matrix smart piezoelectric composite piece encapsulated in a cement mortar formed a practical sensor, and it was tested on material test system with cyclic loading. According to the theoretical analysis, the function of the cement matrix piezoelectric sensor output voltage was expressed in terms of the magnitude of the input cyclic loading amplitude and frequency. The curve fitting of gain function that is defined as sensor‘s gain factor under different frequencies of input loading was carried out. From the results of curve fitting, it is found that the cement matrix smart piezoelectric composite has a simple relationship between input loading and output voltage. Therefore the cement matrix piezoelectric composite sensor is suitable to be applied in structural health monitoring. 相似文献
15.
通过对金属挤压过程流动规律的分析,采用油压传感器、位移传感器、动态应变仪及函数记录仪等仪器,建立力与位移之间的关系曲线。根据该曲线确定金属材料在挤压过程中各阶段的变形与挤压力之间的关系。通过不同入模角和不同变形程度,分析正挤压时金属的流动规律。 相似文献
16.
This paper deals with the along-wind dynamic response of tall buildings passively controlled by Cross-Tensioned Spring Damper
(CTSD) mechanisms. In order to estimate the dynamic response more accurately and efficiently, the building and its CTSD controllers
were considered as a coupled non-classical damping system and a new stochastic response analysis method, complex-modal state-space
method, was proposed based on the combination of complex modes of the structural system rather than on the real-modal decomposition
as usual. As numerical examples, the displacement response of a 2-degree-of-freedom system to white-noise input is first considered
and the validity and accuracy of the proposed method are demonstrated through comparison with the exact results. The wind-induced
dynamic responses of a tall building controlled by two CTSD mechanisms are then analyzed. The calculation results showed that
the proposed method is much more appropriate and accurate than the conventional real-modal decomposition method in the analysis
of dynamic responses of passively controlled tall buildings.
Project (59478034) supported by National Natural Science Foundation of China (NSFC). 相似文献
17.
结合实验室虚拟仪器集成环境(LabVIEW)开发简单的虚拟传感器应用界面,实验制作电涡流传感器。依据工作原理及制作工艺设计了合理的电涡流传感器的结构及信号调理电路,制作出探头直径为10 mm、测量范围2～3 mm、分辨率0.1 mm的电涡流传感器,并利用多参数曲线拟合方法进行测试标定。实际实验过程及结果表明,研制的传感器性能稳定可靠。 相似文献
18.
黄上恒 《商丘师范学院学报》2000,16(4):36-38
研究了同时处于机械与电学载荷之下的压电陶瓷柱体表面裂纹前缘的应力场和电位移场。求得了应力及电位移的奇异性阶数和相应的两个强度因子。 相似文献
19.
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20.
We made a theoretical study of the carrier distribution and electromechanical fields in a free piezoelectric semiconductor rod of crystals of class 6 mm. Simple analytical expressions for the carrier distribution, electric potential, electric field, electric displacement, mechanical displacement, stress, and strain were obtained from a 1D nonlinear model reduced from the 3D equations for piezoelectric semiconductors. The distribution and fields were found to be either symmetric or antisymmetric about the center of the rod. They are qualitatively the same for electrons and holes. Numerical calculations show that the carrier distribution and the fields are relatively strong near the ends of the rod than in its central part. They are sensitive to the value of the carrier density near the ends of the rod. 相似文献