Torsional Pendulum Analysis

2016 ◽  
Author(s):  
Michael Hess ◽  
Giuseppe Allegra ◽  
Jiasong He ◽  
Kazuyuki Horie ◽  
Joon-Seop Kim ◽  
...  
Keyword(s):  
Torsional Pendulum

A Proposed Experiment Using a Sphere with an Eccentric Cavity for Hypothetical Long-Range Interactions

1997 ◽  
Vol 12 (08) ◽  
pp. 1465-1482 ◽  
Author(s):  
G. L. Klimchitskaya ◽  
V. M. Mostepanenko ◽  
C. Romero ◽  
Ye. P. Krivtsov ◽  
A. Ye. Sinelnikov
Keyword(s):  
Long Range ◽  
High Sensitivity ◽  
Experimental Setup ◽  
Interaction Range ◽  
Steel Sphere ◽  
Long Range Interactions ◽  
Torsional Pendulum ◽  
Additional Interaction ◽  
Homogeneous Gravitational Field ◽  
Degree Type

The constraints are examined which may be obtained for the parameters of long-range hypothetical interactions by the use of the precise experimental setup created originally for the calibration of accelerometers. This setup includes the large rotating steel sphere with a nonconcentric spherical cavity in which the strictly homogeneous gravitational field arises. The field of additional interaction produced by the atoms of the sphere, however, is not homogeneous. The essential features required of the detector of additional interaction which is the torsional pendulum of high sensitivity are discussed. Both the cases of the Yukawa-type and degree-type hypothetical interactions are investigated. It is shown that the known-to-date constraints for Yukawa-type interactions may be strengthened by a factor of 400 in the appropriate interaction range. For the degree-type hypothetical forces decreasing with distance as r-3, r-4 and r-5 correspondingly the known constraints may be strengthened by the factors of 90, 35 and 20. The conclusion is made that with the use of the specially created related setup it will be conceivable to strengthen the constraints for Yukawa-type interactions up to 4500 times over a wide interaction range.

scholarly journals Elastic constants of fused quartz. Change of young's modulus with temperature

1929 ◽  
Vol 122 (789) ◽  
pp. 274-282 ◽  
Keyword(s):  
Shear Modulus ◽  
Elastic Constants ◽  
Torsional Oscillation ◽  
Elastic Solids ◽  
Continuous Increase ◽  
Rate Of Increase ◽  
Fused Quartz ◽  
Torsional Pendulum ◽  
The Mean ◽  
Good Agreement

When fused quartz is heated, its elastic constants for stretch shear and bulk change all increase, a sharp distinction in behaviour from that of most other elastic solids. An elastically-stretched fibre becomes shorter upon heating, and a strained torsion member reduces its twist for a given twisting effort; and so forth. The changes of shear modulus with temperature have been studied in detail (22 to 98° C.) by Threlfall and later by Horton to about 1000° C., who used methods of experiment based upon the changes in period upon heating, of a torsional pendulum having fused quartz as the elastic member. The results of Horton's experiments showed a continuous increase in modulus up to about 880° C. beyond which temperature the modulus rapidly diminished. At 880° C. the modulus was 5·9 per cent, greater than at 15° C. and the mean rate of increase up to 500° C. was 0·85 × 10 -4 per degree Centigrade. The increase is more rapid at lower temperatures, thus, in the interval 20 to 100° C. mean rate of increase per degree Centigrade was found by Horton to be 1·25 × 10 -4 , which is in good agreement with the earlier determinations made by Threlfall. At still lower temperatures, and using the same method of torsional oscillation, Guye and Einhorn-Bodzechowski showed that the mean temperature coefficient in the interval —194° C. to 0° C. is 1·46 × 10 -4 per degree Centigrade, and that there is no major discontinuity in behaviour in this range.

319 Study of internal friction in wire rope by torsional pendulum

2015 ◽  
Vol 2015.68 (0) ◽  
pp. 119-120
Author(s):  
Kosei Mineo ◽  
Atsuyoshi Miura ◽  
Keiji Imado
Keyword(s):  
Internal Friction ◽  
Wire Rope ◽  
Torsional Pendulum

A torsional creep instrument and a torsional pendulum, both with accurate temperature control

1969 ◽  
Vol 8 (2) ◽  
pp. 130-133 ◽  
Author(s):  
C. W. van der Wal ◽  
C. J. Nederveen ◽  
G. A. Schwippert
Keyword(s):  
Temperature Control ◽  
Accurate Temperature ◽  
Torsional Pendulum ◽  
Accurate Temperature Control

Chaotic Motion of a Nonhomogeneous Torsional Pendulum

1997 ◽  
Vol 07 (03) ◽  
pp. 733-740 ◽  
Author(s):  
Jiin-Po Yeh
Keyword(s):  
Total Energy ◽  
Lyapunov Exponents ◽  
Chaotic Motion ◽  
Local Minimum ◽  
Phase Plane ◽  
Nonlinear Oscillations ◽  
Initial Conditions ◽  
Chaotic Motions ◽  
Torsional Pendulum ◽  
Damped Systems

In this paper, the nonlinear oscillations of a nonhomogeneous torsional pendulum are investigated. Chaotic motions are shown to exist in both damped systems with two-well potential and undamped systems with one-well or two-well potential. Autocorrelations of the Poincaré mappings of the motion are presented and shown to be another useful tool to judge whether the system is chaotic. The total energy of the torsional pendulum is explored as well and it is conjectured that the irregularity of the total energy is probably one of the important factors which cause chaos. Lyapunov exponents are used as an indication of chaos in this paper. For systems with two-well potential, the phase-plane trajectories are found to stay in one well if the motion is regular, but jump from one well to another if the motion is chaotic. Making the initial conditions near the local minimum of the two-well potential is proved to be successful in preventing chaos from happening in the undamped systems.

scholarly journals Algorithm for Processing Signals of the Incremental Encoder for Calculating the Angles of Rotation of the Torsional Pendulum

2021 ◽  
Vol 19 (2) ◽  
pp. 25
Author(s):  
V V Tarasov ◽  
A V Churkin ◽  
V N Novikov ◽  
E A Kalentev ◽  
V F Lys ◽  
...  
Keyword(s):  
Torsional Pendulum ◽  
Incremental Encoder

В статье приведен алгоритм обработки сигналов инкрементного датчика для оценки свободных колебаний крутильного маятника при исследовании фрикционных характеристик смазочных материалов применительно к стальным канатам с использованием возможности ПО «PowerGraph». Стальной канат является сложной и гибкой стержневой системой, в которой проволоки имеют форму пространственной спирали (винтовой линии) или двойной спирали. При этом внутренние проволоки стальных канатов находятся внутри и недоступны для прямого исследования, измерения и контроля. Анализ фрикционных характеристик смазочных материалов, используемых в стальных канатах, усугубляется многокомпонентностью и сложной структурой объекта исследования. Экспериментальные методы исследования в этом случае представляют один из наиболее эффективных и достоверных способов оценки эксплуатационных свойств изделия в целом. В основу эксперимента положен процесс затухания вращательных колебаний тяжелого груза, висящего на исследуемом стальном канате. Используемый смазочный материал влияет на такой колебательный процесс, и характеристикой такого влияния является декремент затухания колебательного процесса. В качестве датчика угла использован инкрементный энкодер, установленный соосно исследуемому канату и обеспечивающий разрешение регистрации угла поворота до 0,18 градуса.

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