A Novel Method for Estimating the Neutral Temperature of Continuously Welded Rail

2007 ◽  
Author(s):  
William Shust ◽  
David Read ◽  
F. Brent Jury
Keyword(s):  
Mechanical Modeling ◽  
Railroad Track ◽  
New Device ◽  
Technology Center ◽  
Neutral Temperature ◽  
Data Engineering ◽  
Novel Method ◽  
Engineering Mechanics ◽  
Continuously Welded Rail ◽  
Non Destructive

Traditionally, railroad track is installed so that rails that are welded together into strings longer than 400 feet experience no longitudinal thermal force at rail temperatures of 90 to 115 degrees °F. This rail temperature at which the thermal force is zero is commonly referred to as the rail’s neutral temperature. Rail at temperatures higher than the neutral temperature are in a state of compression, and in cooler temperatures are in tension. Except for the textbook case of a perfectly straight rail, these longitudinal forces must be reacted along the length of the rail via friction and the rail fasteners. A new device is designed to exploit changes in vibration of the rails within these fastenings and yield a non-destructive estimate of the installed neutral temperature. This paper will report on various on-track tests conducted at the Transportation Technology Center, Inc. (TTCI) in Pueblo, CO. This behavior was first noted empirically, without a background engineering mechanics outline. Similarly, this paper will follow the same evolution. After presentation of test data, engineering explanations will follow using theory and mechanical modeling.

Failure Analysis Case Study of a 1.5 Meter Space Flex Harness

2017 ◽  
Author(s):  
Erick Kim ◽  
Kamjou Mansour ◽  
Gil Garteiz ◽  
Javeck Verdugo ◽  
Ryan Ross ◽  
...  
Keyword(s):  
Failure Analysis ◽  
Failure Modes ◽  
Field Of View ◽  
Area Of Interest ◽  
Air Stream ◽  
Novel Method ◽  
Temperature Controlled ◽  
Non Destructive ◽  
Failure Site

Abstract This paper presents the failure analysis on a 1.5m flex harness for a space flight instrument that exhibited two failure modes: global isolation resistances between all adjacent traces measured tens of milliohm and lower resistance on the order of 1 kiloohm was observed on several pins. It shows a novel method using a temperature controlled air stream while monitoring isolation resistance to identify a general area of interest of a low isolation resistance failure. The paper explains how isolation resistance measurements were taken and details the steps taken in both destructive and non-destructive analyses. In theory, infrared hotspot could have been completed along the length of the flex harness to locate the failure site. However, with a field of view of approximately 5 x 5 cm, this technique would have been time prohibitive.

A Novel Method for Rapid Non Destructive Determination of O/W Creams Stability

1982 ◽  
Vol 8 (4) ◽  
pp. 475-485 ◽  
Author(s):  
N. Garti ◽  
S. Magdassi ◽  
A. Rubinstein
Keyword(s):  
Novel Method ◽  
Non Destructive

A Novel Non-Destructive Method for Measuring Elastic Moduli of Cultivated Cartilage Tissues

2007 ◽  
Vol 342-343 ◽  
pp. 853-856 ◽  
Author(s):  
Duk Young Jung ◽  
Yu Bong Kang ◽  
Toshie Tsuchiya ◽  
Sadami Tsutsumi
Keyword(s):  
Mechanical Properties ◽  
Bulk Modulus ◽  
Soft Tissues ◽  
Articular Chondrocytes ◽  
Collagen Gel ◽  
Accuracy And Precision ◽  
Novel Method ◽  
Silicone Rubbers ◽  
High Degree ◽  
Non Destructive

Accurate measurement of the mechanical properties of artificial or cultivated cartilage is a major factor for determining successive regeneration of defective soft tissues. In this study, we developed a novel method that enabled the bulk modulus (k-modulus) to be measured nondestructively using the relationship between volume and pressure of living soft tissues. In order to validate this method we estimated the bulk modulus of soft silicone rubbers using our new method and a conventional method. The results showed a 5 ~ 10% difference between the results obtained with the two methods. Our method was used subsequently to measure the mechanical properties of cultivated cartilage samples (collagen gel type), that had been incubated for four weeks in the presence or absence of human articular chondrocytes (HACs). Our experiments showed that cultivated cartilage tissues grown in the presence of HACs had a higher bulk modulus (120 ± 20 kPa) than samples grown without HACs (90 ± 15 kPa). The results indicated that our novel method offered an effective method for measurement of volume changes in minute living soft tissues, with the measurements having a high degree of accuracy and precision. Furthermore, this method has significant advantages over conventional approaches as it can be used to rapidly and accurately evaluate the strength of soft tissues during cultivation without causing damage to the specimen.

CHARACTERIZATION OF FRICTION WELDED TITANIUM ALLOY AND STAINLESS STEEL WITH A NOVEL INTERLAYER GEOMETRY

2016 ◽  
Vol 24 (05) ◽  
pp. 1750064
Author(s):  
R. KUMAR ◽  
M. BALASUBRAMANIAN
Keyword(s):  
Stainless Steel ◽  
Research Work ◽  
Metal Loss ◽  
304L Stainless Steel ◽  
Surface Geometry ◽  
Optical Micrograph ◽  
Minimum Number ◽  
Novel Method ◽  
Non Destructive

The main purpose of the current research work is to identify and investigate a novel method of holding an intermediate metal and to evaluate its metallurgical and mechanical properties. Copper was used as an interlayer material for the welding of this dissimilar Ti–6Al–4V (Ti alloy) and 304L stainless steel (SS). The study shows that the input parameters and surface geometry played a very significant role in producing a good quality joints with minimum heat affected zone and metal loss. A sound weld was achieved between Ti–6Al–4V and SS304L, on the basis of the earlier experiments conducted by the authors in their laboratory, by using copper rod as intermediate metal. Box–Behnken method was used for performing a minimum number of experiments for the study. In the present study, Ti–6Al–4V alloy and SS304L were joined by a novel method of holding the interlayer and new surface geometry for the interlayer. Initially, the drop test was used for determining the quality of the fabricated joint and, subsequently, non-destructive techniques like radiography and C-scan were used. Further optical micrograph, SEM–EDS, hardness and tensile test were done for understanding the performance of the joint.

Field Testing of Prototype Systems for the Non-Destructive Measurement of the Neutral Temperature of Railroad Tracks

2014 ◽  
Author(s):  
Robert Phillips ◽  
Francesco Lanza di Scalea ◽  
Claudio Nucera ◽  
Mahmood Fateh ◽  
John Choros
Keyword(s):  
Research And Development ◽  
High Speed ◽  
Field Tests ◽  
Field Testing ◽  
Cold Weather ◽  
Rolling Stock ◽  
Prototype System ◽  
Neutral Temperature ◽  
Destructive Measurement ◽  
Non Destructive

In both high speed and freight rail systems, the modern construction method is Continuous Welded Rail (CWR). The purpose of the CWR method is to eliminate joints in order to reduce the maintenance costs for both the rails and the rolling stock. However, the elimination of the joints increases the risk of rail breakage in cold weather and buckling in hot weather. In order to predict the temperature at which the rail will break or buckle, it is critical to have knowledge of the temperature at which the rail is stress free, namely the rail Neutral Temperature. The University of California at San Diego (UCSD) has developed an innovative technique based on non-linear ultrasonic guided waves, under Federal Railroad Administration (FRA) research and development grants for the non-destructive measurement of the Neutral Temperature of CWR. Through the licensing of this technology from UCSD and under the sponsorship of the FRA Office of Research and Development, a field deployable prototype system has been developed and recently field-tested at cooperating railroad properties. Three prototype systems have been deployed to the Burlington Northern Santa Fe (BNSF), AMTRAK, and the Union Pacific (UP) railroads for field testing and related data acquisition for a comprehensive evaluation, with respect to both performance and economy of operation. This paper summarizes the results of these field tests, as compared to well-established techniques such as VERSE and strain gages.

A Novel Method for Contactless, Non Destructive Investigation of Semi Conductor Structures in the SEM.

1997 ◽  
Vol 3 (S2) ◽  
pp. 495-496
Author(s):  
EI Rau ◽  
VNE Robinson
Keyword(s):  
Electron Beam ◽  
Active Sites ◽  
Charge Carriers ◽  
Induced Voltage ◽  
Piv Technique ◽  
Novel Method ◽  
A Charge ◽  
Crystallographic Defects ◽  
Non Destructive ◽  
Charge Carrier Capture

It is known that scanning a focussed laser beam across the surface of a semi conductor wafer, can produce a photon induced voltage (PIV) at electrically active sites. This technique depends upon the incident photons inducing charge carriers, both electrons and holes, on or just below the surface of the semi conductor. These charge carriers drift through the device until they are captured by a defect, at which stage they accumulate, producing a voltage at the surface. These voltages are only associated with a charge carrier capture site, which means that a voltage build up only occurs at a defect. This PIV technique has been used for contactless imaging of semiconductor wafers, allowing easy identification of electrically active sites such as crystallographic defects, imperfections and inhomogenieties on or just below the surface [1,2].Nothing in the above mechanism excludes the use of an electron beam to induce charge carriers and produce an electron induced voltage (EIV).

A Novel Measurement and Qualification Method of GMAW Welding Fault Based on Digital Signals

2012 ◽  
Vol 472-475 ◽  
pp. 1201-1205
Author(s):  
Sheng Qiang Feng ◽  
Guo Ping Ling ◽  
Bing Ma ◽  
Sheng Sun Hu
Keyword(s):  
Mahalanobis Distance ◽  
Welding Process ◽  
Welding Current ◽  
The Other ◽  
Digital Signals ◽  
High Quality ◽  
Calculation Results ◽  
Novel Method ◽  
Non Destructive ◽  
Gmaw Welding

Online fault non-destructive detection is crucial to the fabrication of high quality products of welds. In this study, a novel method in the field of weld whose name is Mahalanobis Distance Measurement (MDM) is illustrated and employed to determine whether welding faults have occurred or not. This method is based on an arc method which is employed to get the information of welding voltage and welding current. Through analyzing the calculation results of Mahalanobis Distance of the welding voltage and current signals, the important information of welding process has been obtained. At the meanwhile, whether a fault has occurred or not is decided. In order to verify the effect of the performance of the different width of the gap on the results of Mahalanobis Distance, two widths of the gap generated artificially were chosen: one is 2 mm and the other is 3 mm. The results of the experiment have demonstrated that using the thinking of Mahalanobis Distance to measure the weld faults is feasible.

Field testing of prototype systems for the non-destructive measurement of the neutral temperature of railroad tracks

2014 ◽  
Author(s):  
Robert Phillips ◽  
Francesco Lanza di Scalea ◽  
Claudio Nucera ◽  
Mahmood Fateh ◽  
John Choros
Keyword(s):  
Field Testing ◽  
Railroad Tracks ◽  
Neutral Temperature ◽  
Destructive Measurement ◽  
Non Destructive
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