Determination of Tensile Properties by a Three-Point Method

1986 ◽  
Vol 108 (3) ◽  
pp. 218-221
Author(s):  
E. G. Thomsen ◽  
F. D. Negroni

It is shown that it is possible to use a three-point method for the evaluation of tensile data for some ductile metals. The experimental data show also that average tensile stresses and axial tensile stresses along the axis of the specimens during the necking portion of a test remain linear functions of the effective strain. Prediction made by the use of an electronic calculation sheet and the use of a computer program yield results which are in substantial agreement with the experimental results. The three-point method would seem to reduce the experimental work necessary to obtain σ versus ε curves and apparently would permit higher testing speeds than those of ε ≈ 0.03 used in this investigation.

1. The equations of motion of viscous fluid (obtained by grafting on certain terms to the abstract equations of the Eulerian form so as to adapt these equations to the case of fluids subject to stresses depending in some hypothetical manner on the rates of distortion, which equations Navier seems to have first introduced in 1822, and which were much studied by Cauchy and Poisson) were finally shown by St. Venant and Sir Gabriel Stokes, in 1845, to involve no other assumption than that the stresses, other than that of pressure uniform in all directions, are linear functions of the rates of distortion, with a co-efficient depending on the physical state of the fluid. By obtaining a singular solution of these equations as applied to the case of pendulums in steady periodic motion, Sir G. Stokes was able to compare the theoretical results with the numerous experiments that had been recorded, with the result that the theoretical calculations agreed so closely with the experimental determinations as seemingly to prove the truth of the assumption involved. This was also the result of comparing the flow of water through uniform tubes with the flow calculated from a singular solution of the equations so long as the tubes were small and the velocities slow. On the other hand, these results, both theoretical and practical, were directly at variance with common experience as to the resistance encountered by larger bodies moving with higher velocities through water, or by water moving with greater velocities through larger tubes. This discrepancy Sir G. Stokes considered as probably resulting from eddies which rendered the actual motion other than that to which the singular solution referred and not as disproving the assumption.


1981 ◽  
Vol 7 (4) ◽  
pp. 211-216
Author(s):  
György Fodor ◽  
Miklós Szilágyi ◽  
László Zombory

This paper describes the determination of the sheet resistance of a narrow strip located in a homogeneous resistive layer of different resistivity. The application of the method for the evaluation of inhomogeneous layers used for thermoprinter head production is discussed.


2003 ◽  
Vol 62 (2) ◽  
pp. 129-137 ◽  
Author(s):  
D. Bigaud ◽  
C. Szostkiewicz ◽  
P. Hamelin

2020 ◽  
Vol 10 (17) ◽  
pp. 5726
Author(s):  
Rafael López-Núñez ◽  
Fátima Ajmal-Poley ◽  
Pilar Burgos-Doménech

Portable X-ray fluorescence (pXRF) has been a widely used technique in various applications. However, its use for the analysis of organic amendments (composts, sewage sludges, organic fertilizers) is scarce. In these matrices, concentrations of some elements are below their detection limit. The objective of this work was to find multiple linear regression equations that were able to predict the aqua-regia-soluble concentrations of the elements As, Cd, Cr, Hg, Ni, and Se using the pXRF readings of other measurable elements as predictor variables. For this, a set of 30 samples of organic amendments (composts, sewage sludges, and organic fertilizers) from the Manure and Refuse Sample Exchange Programme of the Wageningen Evaluating Programs for Analytical Laboratories (MARSEP-WEPAL) was used. Several amendment type-dependent single or multiple linear functions were found based on 1, 2, or 3 predictors. The predictor readings corresponded to the concentration of elements of geogenic (Fe, Si, Ti, Cl, Zr Al, Ca, S, Mn, and Ba), anthropogenic (Zn and Pb), and agricultural (P and K) origin. The regression coefficients of these functions were r = 0.90–0.99; therefore, they allowed for the quantitative determination of the target elements. These results will allow for fast and reliable analysis of organic amendments using pXRF that is valid for quality control in treatment plants.


1988 ◽  
Vol 61 (5) ◽  
pp. 879-891 ◽  
Author(s):  
Robert H. Finney ◽  
Alok Kumar

Abstract The determination of the material coefficients for Ogden, Mooney-Rivlin, Peng, and Peng-Landel material models using simple ASTM D 412 tensile data is shown to be a manageable task. The application of the various material models are shown to be subject to the type and level of deformation expected, with Ogden showing the best correlation with experimental data over a large strain range for the three types of strain investigated. At low strains, all of the models showed reasonable correlation.


Sign in / Sign up

Export Citation Format

Share Document