Railroad Axle Design Factors

1968 ◽  
Vol 90 (1) ◽  
pp. 33-42 ◽  
Author(s):  
R. Byrne
Keyword(s):  
Reference Material ◽  
Fatigue Tests ◽  
Railroad Axle ◽  
Design Factors

Railroad axle designs have been developed from an application of theoretical principles of Reuleaux combined with extensive laboratory fatigue studies supplemented to some extent by road service tests. The designer is presented with data on the effects of the complex forces acting on axles operating in railroad service. Criteria for wheel seat and axle body stresses established from fatigue tests and modified by practical considerations are discussed. The paper gives elaborate reference material for use by future investigators of axle properties and designs.

scholarly journals Prediction of fatigue life of aluminum 2024-T3 at low temperature by finite element analysis

2020 ◽  
Vol 14 (3) ◽  
pp. 7170-7180
Author(s):  
S. Mazlan ◽  
N. Yidris ◽  
R. Zahari ◽  
E. Gires ◽  
D.L.A. Majid ◽  
...  
Keyword(s):  
Fatigue Life ◽  
Low Temperature ◽  
Load Ratio ◽  
Fatigue Tests ◽  
Element Analysis ◽  
Cooling Chamber ◽  
Loading Tests ◽  
Cyclic Loading Tests ◽  
Design Factors ◽  
Ansys Workbench

The change in material properties at low temperature has always been one of the concerned design factors in aircraft industries. The wings and fuselage are repeatedly exposed to sub zero temperature during cruising at high altitude. In this study, fatigue tests were conducted on standard flat specimens of aluminum 2024-T3 at room temperature and at -30 °C. The monotonic and cyclic loading tests were conducted using MTS 810 servo hydraulic machine equipped with a cooling chamber. The monotonic tests were conducted at a crosshead speed rate of 1 mm/min and the cyclic tests at a frequency of 10 Hz with a load ratio of 0.1. The experimental data obtained, such as the yield strength, ultimate strength and S-N curve were used as the input parameters in ANSYS Workbench 16.1. This close agreement demonstrates that the isotropic model in ANSYS workbench is essential in predicting fatigue life. The increase in stress parameter causes fatigue life to decrease. Besides, the decrease in temperature causes the total fatigue life to increase.

Multi-Center Calibration of the Second Reference Material for Thromboplastin, Rabbit, Plain, Coded CRM 149R

1991 ◽  
Vol 65 (03) ◽  
pp. 263-267 ◽  
Author(s):  
A M H P van den Besselaar ◽  
R M Bertina
Keyword(s):  
Reference Material ◽  
Standard Error ◽  
Standard Errors ◽  
Sensitivity Index ◽  
Long Term Stability ◽  
Significant Bias ◽  
The Mean ◽  
The Relationship ◽  
International Sensitivity Index

SummaryIn a collaborative trial of eleven laboratories which was performed mainly within the framework of the European Community Bureau of Reference (BCR), a second reference material for thromboplastin, rabbit, plain, was calibrated against its predecessor RBT/79. This second reference material (coded CRM 149R) has a mean International Sensitivity Index (ISI) of 1.343 with a standard error of the mean of 0.035. The standard error of the ISI was determined by combination of the standard errors of the ISI of RBT/79 and the slope of the calibration line in this trial.The BCR reference material for thromboplastin, human, plain (coded BCT/099) was also included in this trial for assessment of the long-term stability of the relationship with RBT/79. The results indicated that this relationship has not changed over a period of 8 years. The interlaboratory variation of the slope of the relationship between CRM 149R and RBT/79 was significantly lower than the variation of the slope of the relationship between BCT/099 and RBT/79. In addition to the manual technique, a semi-automatic coagulometer according to Schnitger & Gross was used to determine prothrombin times with CRM 149R. The mean ISI of CRM 149R was not affected by replacement of the manual technique by this particular coagulometer.Two lyophilized plasmas were included in this trial. The mean slope of relationship between RBT/79 and CRM 149R based on the two lyophilized plasmas was the same as the corresponding slope based on fresh plasmas. Tlowever, the mean slope of relationship between RBT/79 and BCT/099 based on the two lyophilized plasmas was 4.9% higher than the mean slope based on fresh plasmas. Thus, the use of these lyophilized plasmas induced a small but significant bias in the slope of relationship between these thromboplastins of different species.

Effect of Concentration of Trisodium Citrate Anticoagulant on Calculation of the International Normalised Ratio and the International Sensitivity Index of Thromboplastin

1994 ◽  
Vol 72 (01) ◽  
pp. 084-088 ◽  
Author(s):  
E M Duncan ◽  
C R Casey ◽  
B M Duncan ◽  
J V Lloyd
Keyword(s):  
Reference Material ◽  
Oral Anticoagulants ◽  
Reference Method ◽  
Trisodium Citrate ◽  
Sensitivity Index ◽  
Blood Samples ◽  
Orthogonal Regression ◽  
Significant Difference ◽  
International Normalised Ratio ◽  
International Sensitivity Index

SummaryThe aim of this study was to determine whether the concentration of trisodium citrate used to anticoagulate blood has an effect on the INR of the sample and the ISI of the thromboplastin. Five thromboplastins including and Australian reference material were used to measure the prothrombin time of normal and patient samples collected into two concentrations of trisodium citrate - 109 mM and 129 mM. There was no effect of citrate concentration on the INRs determined with the reference material. However for the other four thromboplastins there was a significant difference between INRs for the two citrate groups. The prothrombin times of the samples collected into 129 mM were longer than those collected into 109 mM. This difference was only slight in normal plasma but more marked in patients receiving oral anticoagulants, causing the INRs for patient plasmas collected into 129 mM citrate to be higher then the corresponding samples collected into 109 mM citrate.From orthogonal regression of log prothrombin times by the reference method against each thromboplastin, we found that the ISI for each thromboplastin was approximately 10% lower when determined with samples collected into 129 mM citrate than with samples collected into 109 mM. These results suggest that the concentration of trisodium citrate used for collection of blood samples can affect the calculation of the INR and the calibration of the ISI of thromboplastin. This was found both for commercial thromboplastins prepared by tissue extraction and for a recombinant tissue factor.

BIOASSAY CHARACTERISTICS OF INDIVIDUAL URINARY GONADOTROPHIN EXTRACTS

1963 ◽  
Vol 42 (2) ◽  
pp. 214-224
Author(s):  
Raymond C. Mellinger ◽  
Jalileh A. Mansour ◽  
Richmond W. Smith
Keyword(s):  
Reference Material ◽  
Young Women ◽  
Reference Standard ◽  
General Acceptance ◽  
Modifying Factors ◽  
Large Numbers ◽  
The World ◽  
Quantitative Bioassay ◽  
Different Parts ◽  
Age And Sex

ABSTRACT A reference standard is widely sought for use in the quantitative bioassay of pituitary gonadotrophin recovered from urine. The biologic similarity of pooled urinary extracts obtained from large numbers of subjects, utilizing groups of different age and sex, preparing and assaying the materials by varying techniques in different parts of the world, has lead to a general acceptance of such preparations as international gonadotrophin reference standards. In the present study, however, the extract of pooled urine from a small number of young women is shown to produce a significantly different bioassay response from that of the reference materials. Gonadotrophins of individual subjects likewise varied from the multiple subject standards in many instances. The cause of these differences is thought to be due to the modifying influence of non-hormonal substances extracted from urine with the gonadotrophin and not necessarily to variations in the gonadotrophins themselves. Such modifying factors might have similar effects in a comparative assay of pooled extracts contributed by many subjects, but produce significant variations when material from individual subjects is compared. It is concluded that the expression of potency of a gonadotrophic extract in terms of pooled reference material to which it is not essentially similar may diminish rather than enhance the validity of the assay.

Fatigue Tests on Prestressed Concrete Beams Made With Debonded Strands

PCI Journal ◽  
1994 ◽  
Vol 39 (6) ◽  
pp. 70-88
Author(s):  
Bruce W. Russell ◽  
Ned H. Burns
Keyword(s):  
Prestressed Concrete ◽  
Concrete Beams ◽  
Fatigue Tests

HIGH SPEED FATIGUE TESTS on SMALL SPECIMENS of PLAIN

PCI Journal ◽  
1959 ◽  
Vol 4 (2) ◽  
pp. 53-70 ◽  
Author(s):  
BASIL M. ASSIMACOPOULOS ◽  
ROBERT F. WARNER ◽  
CARL E. EKBERG, JR.
Keyword(s):  
High Speed ◽  
Fatigue Tests

Phase Lag of Tire Cornering Force

1989 ◽  
Vol 17 (3) ◽  
pp. 184-200 ◽  
Author(s):  
R. Hanada ◽  
T. Nagumo ◽  
T. Mashita
Keyword(s):  
Phase Lag ◽  
Design Elements ◽  
Radial Location ◽  
Radial Stiffness ◽  
Design Factors

Abstract Automobile handling can be greatly improved by reducing the phase lag of tire cornering force behind imposed distortion. We have shown experimentally that this lag is related to in-plane stiffness of the belt and to radial, lateral, and circumferential stiffnesses of the sidewall. While the cornering stiffness is related to the belt rigidity, either can be changed without affecting the sidewall stiffnesses. The cornering stiffness, for example, is sensitive to design factors such as tread compound and tread pattern. The radial, lateral, and circumferential sidewall stiffnesses, however, are mutually perpendicular at a given point in a tire, so they cannot be changed independently of each other. In order to reduce the phase lag of the cornering force, the lateral and circumferential stiffnesses must be increased with a minimum increase in radial stiffness. This can be done by either lowering the radial location of the maximum section width of the inflated tire or by proper changes in material and/or design elements of the sidewall.

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