Overstrain Tests on Thick-Walled Cylinders

1960 ◽  
Vol 82 (2) ◽  
pp. 103-116 ◽  
Author(s):  
S. M. Jorgensen
Keyword(s):  
Experimental Data ◽  
Strain Hardening ◽  
Experimental Work ◽  
Theoretical Method ◽  
Bursting Strength ◽  
Strength Based ◽  
Stress Levels ◽  
Simplified Formula

The experimental work described in the following covers pressure-expansion tests on thick-walled, closed-end cylinders of four different steels. The tests covered stress levels through the plastic and strain-hardening ranger to destruction, at pressures up to 100,000 psi. A theoretical method is given for computing expansion and bursting strength, based on both tension and torsion data. Finally, a simplified formula for ultimate pressures is described and checked against the experimental data.

In Reply: Combinations of Antibiotics

PEDIATRICS ◽  
1960 ◽  
Vol 26 (3) ◽  
pp. 499-499
Author(s):  
Robert J. Haggerty
Keyword(s):  
Experimental Data ◽  
Clinical Data ◽  
Experimental Work ◽  
The Subject ◽  
Antimicrobial Combinations

I am delighted to have Dr. Jawetz again bring to the attention of your readers his definitive work on the subject of antimicrobial combinations. We certainly have no quarrel with the points he reiterates. Our choice of words, "It is not clear why these results are at variance with the experimental data of Jawetz or the clinical data of Lepper and Dowling," was probably unfortunate, for Dr. Jawetz points out why the results did differ from his experimental work.

Statistical Design of Fatigue Experiments

1952 ◽  
Vol 19 (1) ◽  
pp. 109-113
Author(s):  
Waloddi Weibull
Keyword(s):  
Experimental Data ◽  
Statistical Design ◽  
Testing Time ◽  
Optimum Distribution ◽  
Analytical Expression ◽  
Optimum Choice ◽  
Stress Levels ◽  
Parameter Values ◽  
Applied Stresses

Abstract An analytical expression connecting fatigue lives with applied stresses, and methods for computing the values of its parameters from experimental data are given. Formulas for estimating the uncertainty of computed parameter values, caused by scatter of loads and fatigue lives, for optimum distribution of specimens, and for optimum choice of stress levels, are deduced. Testing time and costs may be reduced by more than 40 per cent by using the formulas.

scholarly journals β-γ and isomeric decay spectroscopy of 168Dy

2018 ◽  
Vol 178 ◽  
pp. 02023
Author(s):  
G.X. Zhang ◽  
H. Watanabe ◽  
F.G. Kondev ◽  
G.J. Lane ◽  
P.H. Regan ◽  
...  
Keyword(s):  
Experimental Data ◽  
Excited States ◽  
Experimental Work ◽  
Isomeric State ◽  
Level Structure ◽  
Primary Beam ◽  
Average Intensity ◽  
Experimental Procedure ◽  
Preliminary Results ◽  
Decay Spectroscopy

This contribution will report on the experimental work on the level structure of 168Dy. The experimental data have been taken as part of the EURICA decay spectroscopy campaign at RIBF, RIKEN in November 2014. In the experiment, a 238U primary beam is accelerated up to 345 MeV/u with an average intensity of 12 pnA. The nuclei of interest are produced by in-flight fission of 238U impinging on Be target with a thickness of 5 mm. The excited states of 168Dy have been populated through the decay from a newly identified isomeric state and via the β decay from 168Tb. In this contribution, scientific motivations, experimental procedure and some preliminary results for this study are presented.

scholarly journals Моделирование проводимости Капицы через шероховатые интерфейсы между твердыми телами

2021 ◽  
Vol 63 (7) ◽  
pp. 982
Author(s):  
Б. Лю ◽  
В.И. Хвесюк ◽  
А.А. Баринов
Keyword(s):  
Experimental Data ◽  
Theoretical Prediction ◽  
Transmission Coefficient ◽  
Wide Temperature Range ◽  
Acoustic Waves ◽  
Theoretical Method ◽  
Interface Roughness ◽  
Kapitza Conductance ◽  
Acoustic Mismatch ◽  
The Difference

In this work, we have formulated and solved the problem of determining the Kapitza conductance across the interface between two solids, taking into account the interface roughness. We use a modified acoustic mismatch model (AMM). The difference from the classic model is that the dispersion properties of acoustic waves are considered. A significant advantage of this model is that the theoretical prediction agrees well with experimental data over a wide temperature range: from 30K to more than 300K. Finally, a theoretical method with the statistical distribution of roughness profiles is used to determine the energy transmission coefficient across the interface.

Velocity Profiles of Turbulent Boundary Layers

1969 ◽  
Vol 73 (698) ◽  
pp. 143-147 ◽  
Author(s):  
M. K. Bull
Keyword(s):  
Experimental Data ◽  
Boundary Layer ◽  
Turbulent Boundary Layer ◽  
Velocity Profile ◽  
Boundary Layers ◽  
Experimental Work ◽  
Constant Pressure ◽  
Velocity Profiles ◽  
Turbulent Boundary Layers ◽  
Boundary Layer Equations

Although a numerical solution of the turbulent boundary-layer equations has been achieved by Mellor and Gibson for equilibrium layers, there are many occasions on which it is desirable to have closed-form expressions representing the velocity profile. Probably the best known and most widely used representation of both equilibrium and non-equilibrium layers is that of Coles. However, when velocity profiles are examined in detail it becomes apparent that considerable care is necessary in applying Coles's formulation, and it seems to be worthwhile to draw attention to some of the errors and inconsistencies which may arise if care is not exercised. This will be done mainly by the consideration of experimental data. In the work on constant pressure layers, emphasis tends to fall heavily on the author's own data previously reported in ref. 1, because the details of the measurements are readily available; other experimental work is introduced where the required values can be obtained easily from the published papers.

scholarly journals WAVE FORCES ON SQUARE CAISSONS

1976 ◽  
Vol 1 (15) ◽  
pp. 132 ◽  
Author(s):  
G.R. Mogridge ◽  
W.W. Jamieson
Keyword(s):  
Experimental Data ◽  
Theoretical Method ◽  
Wave Forces ◽  
Simple Method ◽  
Method Of Calculation ◽  
Wave Flume ◽  
Wide Range ◽  
Wave Heights ◽  
And Storage ◽  
Water Depths

The forces and overturning moments exerted by waves on large vertical square-section caissons have been measured in the laboratory. Each model caisson extended from the bottom of a wave flume through the water surface and was oriented either with one side perpendicular to the direction of wave propagation or turned through an angle of forty-five degrees to this position. For a given orientation, each model was tested for a range of wave heights (up to the point of breaking) for various wave periods and water depths. A digital computer was used for the acquisition, processing, plotting and storage of the experimental data. In addition to the experimental work, an approximate theoretical method is presented which allows the wave loadings on a square caisson to be estimated by means of a simple desk calculation. The experimental data shows that this simple method of calculation is reasonably accurate over a wide range of wave conditions and caisson sizes.

Constitutive Modeling of Porous Shape Memory Alloys Using Gurson–Tvergaard–Needleman Model Under Isothermal Conditions

2020 ◽  
Vol 12 (04) ◽  
pp. 2050038
Author(s):  
Xiang Zhu ◽  
Liangliang Chu ◽  
Guansuo Dui
Keyword(s):  
Experimental Data ◽  
Phase Transformation ◽  
Shape Memory Alloys ◽  
Shape Memory ◽  
Strain Hardening ◽  
Constitutive Relationship ◽  
Model Parameters ◽  
Gtn Model ◽  
Critical Phase ◽  
Transformation Stress

Based on the Gurson–Tvergaard–Needleman (GTN) model, a constitutive relationship considering both the effects of strain hardening and hydrostatic stress for porous shape memory alloys (SMAs) is proposed. To capture the relationship between microscopic and mesoscopic behaviors, a representative volume element (RVE) containing an array of spherical voids is presented. In this paper, an approximate solution including strain hardening exponent [Formula: see text] is deduced by considering the porous SMA as a two phase composite with the SMA matrix and the second phase representing voids. The model parameters, [Formula: see text] and [Formula: see text], accounting for interactions between voids are investigated to take into account their influences on strain hardening, critical phase transformation stress and yield surface. In addition, the evolution equations of phase transformation are derived and then applied to the simulation of porous Ni–Ti SMAs with a porosity of 13%. Using the calibrated GTN model parameters, the critical phase transformation stress closer to experimental data is obtained. The predictions of stress–strain curve by the proposed constitutive model are found to be in excellent agreement with published experimental data and finite element results. The results prove that the model is capable of reproducing the features of porous SMAs such as superelasticity, tensile-compressive asymmetry and internal loops under uniaxial even combined loading conditions. A conclusion is drawn that the present constitutive relationship is powerful and useful for the analysis of porous SMAs.

Electrical Conduction in Granular Metal Films

1990 ◽  
Vol 195 ◽  
Author(s):  
J.E. Morris ◽  
A. Mello ◽  
C.J. Adkins
Keyword(s):  
Experimental Data ◽  
Particle Size ◽  
Recent Work ◽  
Electrical Conduction ◽  
Experimental Work ◽  
Field Effect ◽  
Metal Particle ◽  
Metal Films ◽  
Metal Particle Size ◽  
Gap Width

ABSTRACTIn the early 1970's, Abeles et al developed a widely accepted model for electrical conduction in granular metal films based upon an assumed correlation between metal particle size and inter-particle tunneling gap width. The paper critically examines this assumption and other aspects of the theory. No observation of any such correlation has been reported, nor should it be expected, particularly in discontinuous films. The latter point requires separate considerations of the very different structures of discontinuous metal films, granular metals and cermets, using the “granular” term here in a more limited sense than usual.Other aspects of the theory considered include its implied percolation topology and the field effect. Experimental data are also re-evaluated in terms of other common models. The paper concludes with a brief review of recent work in discontinuous metal films with suggestions for future theoretical and experimental work.

Analysis of Screw-Expander Performance

1989 ◽  
Vol 203 (1) ◽  
pp. 15-20 ◽  
Author(s):  
K C Ng ◽  
T B Lim ◽  
T Y Bong
Keyword(s):  
Experimental Data ◽  
Experimental Work ◽  
Empirical Model ◽  
Saturated Steam ◽  
Polytropic Index ◽  
Work Output ◽  
Predicted Values ◽  
Good Agreement ◽  
Thermodynamic Processes

The paper examines the thermodynamic processes of a helical screw-expander that operates with dry saturated steam at its inlet. The work output of the screw-expander is analysed using a simple ‘pseudo-polytropic’ index. Using the available experimental data from the literature, an empirical model for the prediction of work using the ‘pseudo-polytropic’ indices is formulated. The expansion indices are expressed in terms of built-in volumetric and pressure ratios; how they are formulated is usually given in an expander specification. Based on the empirical model, there is a good agreement between the experimental work and the predicted values.

Frictional Behavior in Metalworking Processes

1970 ◽  
Vol 92 (4) ◽  
pp. 535-542 ◽  
Author(s):  
M. B. Peterson ◽  
F. F. Ling
Keyword(s):  
Experimental Data ◽  
Surface Roughness ◽  
Shear Strength ◽  
Metal Flow ◽  
Theoretical Work ◽  
Metal Working ◽  
Surface Adhesion ◽  
Frictional Behavior ◽  
Interface Surface ◽  
Strength Based

Frictional behavior in metalworking processes between the tool and the workpiece for unlubricated condition is discussed. The primary aim of the work was to develop means to predict frictional behavior in terms of which metal flow can be better understood. Experimental and theoretical work has been carried out to determine the important variables of metal working friction. It was found that friction is dependent upon the strength of the workpiece, the pressure, the surface adhesion, and the surface roughness. The pressure-dependence of shear strength based on experimental data is also discussed. Finally, although techniques are available to predict friction, they are dependent upon the ability to predict interface surface temperature.

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