Interferometric calibration of a strainmeter transducer

1971 ◽  
Vol 61 (4) ◽  
pp. 937-955
Author(s):  
Stanley Smookler ◽  
John V. Kline

abstract A capacitive-strainmeter transducer is calibrated using a variable-spacing, Fabry-Perot interferometer. Optical flats are mounted on a spring parallelogram. Thermal expansion of a steel tube deforms the parallelogram, smoothly displacing one of the optical flats. This modulates the intensity of the 5016 àline, observed at the central zone of the interference pattern, and thus produces sharp peaks on a pen recorder. A theoretical analysis of the peak width, based on the work of Chabbal (1958), agrees with that recorded by the interferometer. This calibration permits earth-strain measurements to an accuracy of 1 per cent.

Sensors ◽  
2018 ◽  
Vol 18 (10) ◽  
pp. 3393 ◽  
Author(s):  
Jin Cheng ◽  
Yu Zhou ◽  
Xiaoping Zou

Fiber Fabry–Perot cavity sensing probes with high thermal stability for dynamic signal detection which are based on a new method of structure compensation by a proposed thermal expansion model, are presented here. The model reveals that the change of static cavity length with temperature only depends on the thermal expansion coefficient of the materials and the structure parameters. So, fiber Fabry–Perot cavity sensing probes with inherent temperature insensitivity can be obtained by structure compensation. To verify the method, detailed experiments were carried out. The experimental results reveal that the static cavity length of the fiber Fabry–Perot cavity sensing probe with structure compensation hardly changes in the temperature range of −20 to 60 °C and that the method is highly reproducible. Such a method provides a simple approach that allows the as-fabricated fiber Fabry–Perot cavity acoustic sensor to be used for practical applications, exhibiting the great advantages of its simple architecture and high reliability.


Author(s):  
Zhengran Lu ◽  
Yongqin Wen ◽  
Liang Zhao ◽  
Changtie Huang ◽  
Shuo Cao ◽  
...  

2013 ◽  
Vol 662 ◽  
pp. 511-514
Author(s):  
Yi Chun Liu ◽  
Jia Min Zhang ◽  
Jian Hong Yi

Nickel layers with tensile or pressure residual stress were prepared by electroforming technique from two kinds of electrolyte. Subsequent heat treatment was adopted to get the stress released. The coefficients of thermal expansion (CTEs) were measured with a thermal dilatometer and the relationship between residual stress and the measured CTEs was revealed both from experimental results and theoretical analysis.


Author(s):  
Hideo Koguchi ◽  
Atsushi Ueno

In this study, a simple theory for estimating the warpage of chip size packaging (CSP) during a manufacturing process is presented. A single-sided CSP which is composed of IC, a resin and a substrate is modeled for an analysis as a three-layered material. Especially, the resin and the substrate have different thermo-viscoelastic properties. When the layered body is perfectly bonded, its warpage is caused by the difference of the thermal expansion coefficient in each layer when temperature varies. The warpage of CSP for a various thicknesses of the IC and the substrate is investigated. Finally, the warpage calculated using the theory is compared with the result in experiment, and both results are well agreed with each other. Then, it is shown that the simple theoretical analysis is valid. After that, this program is extended to be able to analyze the warpage in a CoC (Chip on Chip), and the result of the analysis is then presented.


2013 ◽  
Vol 652-654 ◽  
pp. 677-682
Author(s):  
Qing Liu ◽  
Yong Qing Huang ◽  
Xiao Feng Duan ◽  
Xin Ye Fan ◽  
Xiao Min Ren ◽  
...  

A novel demultiplexing photodetector which consists of a filtering cavity and a conical absorption cavity is proposed. The filtering cavity is formed by four coupled (Fabry-Pérot)F-P cavities, which can realize flat-top and steep-edge spectral response. The top mirror of the absorption cavity is designed to be conical, which can increase the times of light reflection. Then the quantum efficiency is improved. Through the theoretical analysis and simulation, the peak quantum efficiency of the photodetector is 88.87% around 1550nm. In addition, this photodetector has good performance in the flat-top and steep-edge spectral response: the 0.5dB bandwidth is 0.4nm , the 3dB bandwidth is 0.56nm and the 20dB bandwidth is 0.98nm.


2012 ◽  
Vol 428 ◽  
pp. 103-107
Author(s):  
Shui Xing Zhou ◽  
Lu Li ◽  
Yue Ma ◽  
Ling Jun Li

Based on the constitutive relationship model of general concrete filled steel tube, and combining with the results and theoretical analysis of several self-stress concrete filled steel tubular specimens, the constitutive relationship model of self-stress concrete filled steel tube was established by introducing an improvement coefficient of concrete strength related to self-stress level. The calculations of specimens’ bearing capacity with different sectional steel ratios, values of self-stress and concrete strengths were performed, which were in a good accordance with those of experimental values.


1994 ◽  
Author(s):  
Philipp M. Nellen ◽  
H. Pierhofer ◽  
Rolf Broennimann ◽  
Urs J. Sennhauser

2016 ◽  
Vol 851 ◽  
pp. 739-744
Author(s):  
Bo Li ◽  
Hong Gang Lei ◽  
Xu Yang

In this paper, the author uses ANSYS, the software of finite element analysis, to establish the finite element model, the hot spot stress value of different connection structures of steel tube-welded hollow sphere under uniaxial elongation has been analyzed, the theoretical stress concentration factor of this joint has been obtained. Through the static test on the four typical test-piece, 26 steel tube-welded hollow spherical nodes in total, the actually measured stress concentration factor of the joints has been obtained. The theoretical analysis basically coincides with the law of stress concentration factor obtained from the test results.


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