Dynamic characteristics of measuring instruments

1966 ◽  
Vol 9 (2) ◽  
pp. 169-173
Author(s):  
P. P. Kremlevskii ◽  
N. F. Gonek
Keyword(s):  
Dynamic Characteristics ◽  
Measuring Instruments

scholarly journals A Mathematical Model of the Error of Measuring Instruments for Investigating the Dynamic Characteristics

2018 ◽  
Vol 11 (6) ◽  
pp. 14-19
Author(s):  
Dimitar Dichev ◽  
◽  
Fotini Kogia ◽  
Hristiyana Nikolova ◽  
Dimitar Diakov ◽  
...  
Keyword(s):  
Mathematical Model ◽  
Dynamic Characteristics ◽  
Measuring Instruments

Experimental Analysis of the Dynamic Characteristics of a Hybrid Aerostatic Bearing

2012 ◽  
Vol 134 (8) ◽  
Author(s):  
Laurent Rudloff ◽  
Mihai Arghir ◽  
Olivier Bonneau ◽  
Sébastien Guingo ◽  
Guillaume Chemla ◽  
...  
Keyword(s):  
Dynamic Characteristics ◽  
Degrees Of Freedom ◽  
Equations Of Motion ◽  
Measuring Instruments ◽  
Rigid Rotor ◽  
Aerostatic Bearing ◽  
Test Rig ◽  
Impulse Turbine ◽  
Dynamic Coefficients ◽  
The Impact

The dynamic characteristics of a hybrid aerostatic bearing are experimentally investigated on a test rig consisting of a rigid rotor driven by an impulse turbine. The rotor is horizontally mounted and is supported by two identical aerostatic bearings. Both the impulse turbine and the aerostatic hybrid bearings are fed with air. The feeding pressures in the bearings can be as high as 7 bars and rotation speeds can reach 60 krpm so the dynamic load on the rotor is much larger than the static load engendered by its weight. Excitations are applied either via an impact hammer or via unbalancing masses. The measuring instruments record the bearing feeding pressures, the rotation speed, the impact force, the displacements of the two bearings, and the bearing housing accelerations. The experimental data together with the equations of motion of the rotor enables the identification of the dynamic coefficients of the bearings. A second identification procedure using the same impact hammer is also possible as force transducers are mounted between the bearing housing and its support. The dynamic coefficients of the bearings can then be obtained from the equation of motion of its housing. Unbalance response provide a convenient way for verifying the accuracy of the identified dynamic coefficients. Therefore these coefficients are injected in the equations of motion of a four degrees of freedom rigid rotor and the theoretical results are compared with values measured on the test rig. Comparisons show that predictions are acceptable but become less accurate at high rotation speeds where large dynamic forces are needed for exciting the corresponding synchronous frequencies.

scholarly journals Determining the dynamic characteristics of elastic shell structures

2021 ◽  
Vol 6 (7 (114)) ◽  
Author(s):  
Irina Polyakova ◽  
Raikhan Imambayeva ◽  
Bakyt Aubakirova
Keyword(s):  
Dynamic Characteristics ◽  
Natural Frequencies ◽  
Elastic Shell ◽  
Physical And Mechanical Properties ◽  
Frequency Characteristics ◽  
Dynamic Loads ◽  
Measuring Instruments ◽  
Building Structures ◽  
Elastic Elements

Building structures are very often operated under the action of dynamic loads, both natural and man-made. The calculation of structures under the influence of static loads has been quite widely studied in detail. When structures are exposed to dynamic loads, additional tests are carried out, where measuring instruments are installed on the structures to register stresses and deformations that occur during dynamic influences. Elastic elements are the responsible functional unit of many measuring instruments. Therefore, the quality of elastic elements ensures the operational stability of the entire structure. This determines the increased attention that is paid to technology and construction to elastic elements. Previously, the work of elastic elements made of homogeneous mono materials with the same physical and geometric properties in all directions and over the entire surface of the element was studied. The elastic element was considered as a shell of rotation with a complex shape of the meridian and various physical and mechanical properties at various points caused by uneven reinforcement. Two types of reinforcement were implied ‒ radial and circular. Elastic shell elements (ESE) operate under conditions of dynamic loading. The equation was derived for determining the dynamic characteristics of inhomogeneous elastic elements. The dependences of the first three natural frequencies of oscillations on the thickness of the shell and the depth of the corrugation and the first two natural frequencies of oscillations on the thickness of the shell have been analyzed. The amplitude-frequency characteristics (AFC) and the phase-frequency characteristics (PFC) of the shell depending on the geometric parameters have been calculated. All these results could significantly improve the quality of the readings of the instruments, which depend on the sensitivity of the shell elastic elements. And it, in turn, depends on the geometric and physical properties of the shell elastic elements.

scholarly journals A Mathematical Model of the Error of Measuring Instruments for Investigating the Dynamic Characteristics

2018 ◽  
Vol 11 (6) ◽  
pp. 14-19
Author(s):  
Dimitar Dichev ◽  
◽  
Fotini Kogia ◽  
Hristiyana Nikolova ◽  
Dimitar Diakov ◽  
...  
Keyword(s):  
Mathematical Model ◽  
Dynamic Characteristics ◽  
Measuring Instruments

Concept of a new PZT

1978 ◽  
Vol 48 ◽  
pp. 271-278
Author(s):  
Chr. Kühne
Keyword(s):  
Mirror System ◽  
Measuring Instruments

The PZT according to MARKOWITZ, undoubtedly one of the most accurate measuring instruments, has become an integral part of astronomy in the last years. Yet there are two reasons why I still tried to improve the MARKOWITZ basic idea.For the MARKOWITZ process the use of a lens objective is imperative. Because of the diameter limitations of the lens objectives the magnitude is reduced. Although a 65 cm PZT has been put into operation in Washington recently, the thermal difficulties encountered made it necessary to control the temperature actively. In addition, the 65 cm diameter of a lens equipped with 4 elements can be considered as the very limit, but not for a mirror system.In addition there are still more disadvantages using lens objectives. The useable field is restricted by astigmatism, reducing the range of declination. The transmission, especially in the blue wavelengths, decreases very rapidly with the thickness of lenses. For large multilens objectives the transmission is less than for a mirror system.

Invited PaperTemperature dependence of SiGe HBT static and dynamic characteristics

1998 ◽  
Vol 08 (PR3) ◽  
pp. Pr3-81-Pr3-86
Author(s):  
F. Aniel ◽  
N. Zerounian ◽  
A. Gruhle ◽  
C. Mähner ◽  
G. Vernet ◽  
...  
Keyword(s):  
Dynamic Characteristics ◽  
Static And Dynamic Characteristics ◽  
Sige Hbt
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