An inexpensive torsional pendulum apparatus for rigidity modulus measurement

1979 ◽  
Vol 47 (7) ◽  
pp. 632-633 ◽  
Author(s):  
S. Tyagi ◽  
A. E. Lord
2000 ◽  
Vol 649 ◽  
Author(s):  
G. Feng ◽  
A.H.W. Ngan

ABSTRACTDuring the unloading segment of nanoindentation, time dependent displacement (TDD) accompanies elastic deformation. Consequently the modulus calculated by the Oliver-Pharr scheme can be overestimated. In this paper we present evidences for the influence of the measured modulus by TDD. A modification method is also presented to correct for the effects of TDD by extrapolating the TDD law in the holding process to the beginning of the unloading process. Using this method, the appropriate holding time and unloading rate can be estimated for nanoindentation test to minimise the effects of TDD. The elastic moduli of three materials computed by the modification method are compared with the results without considering the TDD effects.


Measurement ◽  
2021 ◽  
Vol 175 ◽  
pp. 108984
Author(s):  
Jianhua Tang ◽  
Lezhang Liu ◽  
Li Jiang ◽  
Hui Huang ◽  
Qiongyao Wang

2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
Bui Duc Tinh ◽  
Nguyen Quang Hoc ◽  
Dinh Quang Vinh ◽  
Tran Dinh Cuong ◽  
Nguyen Duc Hien

The analytic expressions for the thermodynamic and elastic quantities such as the mean nearest neighbor distance, the free energy, the isothermal compressibility, the thermal expansion coefficient, the heat capacities at constant volume and at constant pressure, the Young modulus, the bulk modulus, the rigidity modulus, and the elastic constants of binary interstitial alloy with body-centered cubic (BCC) structure, and the small concentration of interstitial atoms (below 5%) are derived by the statistical moment method. The theoretical results are applied to interstitial alloy FeC in the interval of temperature from 100 to 1000 K and in the interval of interstitial atom concentration from 0 to 5%. In special cases, we obtain the thermodynamic quantities of main metal Fe with BCC structure. Our calculated results for some thermodynamic and elastic quantities of main metal Fe and alloy FeC are compared with experiments.


1997 ◽  
Vol 12 (08) ◽  
pp. 1465-1482 ◽  
Author(s):  
G. L. Klimchitskaya ◽  
V. M. Mostepanenko ◽  
C. Romero ◽  
Ye. P. Krivtsov ◽  
A. Ye. Sinelnikov

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.


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