scholarly journals A comparison of friction modifier performance using two laboratory test scales

2018 ◽  
Vol 233 (2) ◽  
pp. 201-210 ◽  
Author(s):  
L Buckley-Johnstone ◽  
M Harmon ◽  
R Lewis ◽  
C Hardwick ◽  
R Stock
Keyword(s):  
Test Procedure ◽  
Full Scale ◽  
Data Sets ◽  
Test Machine ◽  
Performance Study ◽  
Friction Modifier ◽  
Additional Information ◽  
Large Spread ◽  
Dry Contact ◽  
The University

This paper describes two methods, carried out at two different test scales, for assessing the friction modifier performance. Study A used the wear data from a full-scale rig test at the voestalpine Schienen GmbH and compared it with the wear data from twin disc tests using the SUROS test machine at the University of Sheffield. Study B compared the ‘retentivity’ data, from a full-scale rig at the University of Sheffield, with the data from the SUROS tests. Study A concluded that a good correlation existed between the two scales although assumptions made in the full-scale contact calculation introduce a large spread into the results. There was a greater correlation between the two data sets at more severe contact conditions. Study B showed a different baseline coefficient of traction between the two scales and that a longer test length is required to fully evaluate the ‘retention’ of the friction modifier on the full-scale rig. The paper expands on a previous conference presentation on the same subject. Additional information on the test procedure and test rigs is included here. Surface and subsurface analyses of the SUROS test samples have also been added. The analyses have shown that applying the friction modifier leads to a similar wear mechanism as for the dry contact, but the wear is less severe and there is less subsurface deformation. A discussion describing the differences in test scales and comparing lab tests to field operation is also included.

Fatigue Analysis on a Full Scale Fuselage Panel

2008 ◽  
Vol 385-387 ◽  
pp. 549-552 ◽  
Author(s):  
A. Apicella ◽  
Enrico Armentani ◽  
Stefano Priore
Keyword(s):  
Complex Loading ◽  
Constant Load ◽  
Butt Joint ◽  
Full Scale ◽  
Test Machine ◽  
Fatigue Load ◽  
Element Analysis ◽  
Longitudinal Joint ◽  
Joint Direction ◽  
The University

Fatigue test on a full scale panel with complex loading and geometry has been carried out using a tri-axial test machine specifically designed, built and located in the laboratory of the University of Naples. The aeronautical test panel was designed and manufactured by Alenia. The demonstrator is made up of two skins which are linked by a transversal butt-joint that is parallel to the stringer direction. A fatigue load was applied in the direction normal to the longitudinal joint, while a constant load was applied in the longitudinal joint direction. The demonstrator broke up after about 177000 cycles. Subsequently, a finite element analysis was carried out in order to correlate failure events; due to the biaxial nature of the fatigue loads, Sines criterion was used. The analysis was performed taking into account the different materials of which the panel is composed. The output shows good correlation between experimental data and numerical results, predicting the location on the panel exactly where the failure occurred.

Production of New and Revised A.A.V.S.O. Charts

1979 ◽  
Vol 46 ◽  
pp. 368
Author(s):  
Clinton B. Ford
Keyword(s):  
Variable Star ◽  
Standard Form ◽  
Original Data ◽  
University Of Pennsylvania ◽  
Standard Format ◽  
Additional Information ◽  
The Gift ◽  
The University

A “new charts program” for the Americal Association of Variable Star Observers was instigated in 1966 via the gift to the Association of the complete variable star observing records, charts, photographs, etc. of the late Prof. Charles P. Olivier of the University of Pennsylvania (USA). Adequate material covering about 60 variables, not previously charted by the AAVSO, was included in this original data, and was suitably charted in reproducible standard format.Since 1966, much additional information has been assembled from other sources, three Catalogs have been issued which list the new or revised charts produced, and which specify how copies of same may be obtained. The latest such Catalog is dated June 1978, and lists 670 different charts covering a total of 611 variables none of which was charted in reproducible standard form previous to 1966.

Full Scale Fatigue Experiment on Submarine Pipelines

2014 ◽  
Vol 633-634 ◽  
pp. 659-664 ◽  
Author(s):  
Zong Tao Fang ◽  
De Yu Tang ◽  
Yan Hua Hu ◽  
Hu Li Niu
Keyword(s):  
Welded Joints ◽  
Fatigue Property ◽  
Full Scale ◽  
Small Scale ◽  
Test Machine ◽  
Butt Joints ◽  
Weld Toe ◽  
Small Test ◽  
Weld Root ◽  
Fatigue Experiment

This paper focus on fatigue problem of submarine pipelines, four points bending full scale fatigue experiment were conducted on X65 pipelines butt joints specimens, utilizing pipeline full scale fatigue test machine developed by CNPC. Meanwhile contrast test was also carried out on small specimens. The results show that the fatigue strength of full scale welded joints is lower than the small scale joints. Owing to having no regard for the influence of residual stress and size effect, the small test would provide dangerous results. The fatigue property of full scale welded joints only meets the requirement of DNV C203 W3 curve, and meets the needs of DNV C203 F3 curve basically while not meet BS 7608 F2 curve’s requirements which relatively demand higher. Weld toe and geometric discontinuous near weld root is the weak point for the whole welded joints.

Prevalence Rates for Medical Problems among Flautists: A Comparison of the UNT-Musician Health Survey and the Flute Health Survey

2001 ◽  
Vol 16 (3) ◽  
pp. 99-101
Author(s):  
Cari Spence
Keyword(s):  
Health Survey ◽  
Sleep Disturbances ◽  
Data Sets ◽  
Prevalence Rates ◽  
Medical Problems ◽  
North Texas ◽  
University Of North Texas ◽  
Left Hand ◽  
Significant Difference ◽  
The University

The purpose of this study was to identify prevalence rates of medical problems among flautists. The Flute Health Survey (FHS), a questionnaire with items regarding musculoskeletal and nonmusculoskeletal problems, was distributed at the 1999 National Flute Association annual meeting (n = 40). This questionnaire was pilot tested at the 1999 Texas Flute Festival, which is hosted by the Texas Flute Society. The University of North Texas has posted on the Internet a similar questionnaire regarding the medical problems of all musicians. Responses from the University of North Texas Musician Health Survey (UNT-MHS) were filtered to include only those respondents who denoted flute as their primary instruments (n = 328). Data sets from both surveys were then processed using comparative statistics. Findings show that there was no significant difference between the demographics of the two populations. Only one musculoskeletal site, the left hand, was found to be statistically significant between the two groups. Four nonmusculoskeletal items, depression, earache, headache, and sleep disturbances, were found to be different between the two groups. The overall findings of this comparison show that there are many medical problems facing the flute playing community. Further investigation and observations of this population are necessary.

Design and Full-Scale Testing of M50/P1 Bolt-Down Removeable Bollard System

2018 ◽  
Vol 2672 (41) ◽  
pp. 24-33
Author(s):  
William F. Williams
Keyword(s):  
Urban Areas ◽  
Full Scale ◽  
Shallow Foundations ◽  
Test Installation ◽  
Additional Information ◽  
Performance Requirements ◽  
Crash Testing ◽  
Design And Testing ◽  
Base Plates ◽  
Full Scale Testing

The purpose of this project was to design and test a new bolt-down bollard system that meets the requirements of American Standards for Testing Materials (ASTM) Designation F2656-15 M50/P1 impact conditions. The test installation consisted of three vertical 10-in. diameter (nominal) bollards with welded base plates bolted to a shallow reinforced concrete foundation. The foundation for this system was sized to reduce the foundation embedment. Shallow foundations are often necessary for use in cities and urban areas where utilities can conflict with deeper foundations. Standard common members and materials were used in the installation to accommodate fabrication and installation in locations all over the world. The bollards can be removed to provide access if necessary. Full-scale testing was performed on the bolt-down bollard system. The bollard system design for this project successfully met the requirements of M50/P1 with a total payload penetration of less than 1 m. The new bollard design successfully met all the performance requirements for ASTM F2656-15 M50/P1. Details of the design and testing of the bolt-down bollard system are provided in this paper. Crash-testing videos and additional information on the design and full-scale testing will be provided in the presentation.

scholarly journals Comparison between XBT data and TOPEX/Poseidon satellite altimetry in the Ligurian-Tyrrhenian area

2003 ◽  
Vol 21 (1) ◽  
pp. 123-135 ◽  
Author(s):  
S. Vignudelli ◽  
P. Cipollini ◽  
F. Reseghetti ◽  
G. Fusco ◽  
G. P. Gasparini ◽  
...  
Keyword(s):  
Pilot Project ◽  
Atlantic Water ◽  
Data Sets ◽  
Tyrrhenian Sea ◽  
Satellite Altimeter ◽  
Ligurian Sea ◽  
Data Set ◽  
Additional Information ◽  
Forecasting System ◽  
Computational Errors

Abstract. From September 1999 to December 2000, eXpendable Bathy-Thermograph (XBT) profiles were collected along the Genova-Palermo shipping route in the framework of the Mediterranean Forecasting System Pilot Project (MFSPP). The route is virtually coincident with track 0044 of the TOPEX/Poseidon satellite altimeter, crossing the Ligurian and Tyrrhenian basins in an approximate N–S direction. This allows a direct comparison between XBT and altimetry, whose findings are presented in this paper. XBT sections reveal the presence of the major features of the regional circulation, namely the eastern boundary of the Ligurian gyre, the Bonifacio gyre and the Modified Atlantic Water inflow along the Sicily coast. Twenty-two comparisons of steric heights derived from the XBT data set with concurrent realizations of single-pass altimetric heights are made. The overall correlation is around 0.55 with an RMS difference of less than 3 cm. In the Tyrrhenian Sea the spectra are remarkably similar in shape, but in general the altimetric heights contain more energy. This difference is explained in terms of oceanographic signals, which are captured with a different intensity by the satellite altimeter and XBTs, as well as computational errors. On scales larger than 100 km, the data sets are also significantly coherent, with increasing coherence values at longer wavelengths. The XBTs were dropped every 18–20 km along the track: as a consequence, the spacing scale was unable to resolve adequately the internal radius of deformation (< 20 km). Furthermore, few XBT drops were carried out in the Ligurian Sea, due to the limited north-south extent of this basin, so the comparison is problematic there. On the contrary, the major features observed in the XBT data in the Tyrrhenian Sea are also detected by TOPEX/Poseidon. The manuscript is completed by a discussion on how to integrate the two data sets, in order to extract additional information. In particular, the results emphasize their complementariety in providing a dynamically complete description of the observed structures. Key words. Oceanography: general (descriptive and regional oceanography) Oceanography: physical (sea level variations; instruments and techniques)

scholarly journals Channel-independent recreation of artefactual signals in chronically recorded local field potentials using machine learning

2022 ◽  
Vol 9 (1) ◽  
Author(s):  
Marcos Fabietti ◽  
Mufti Mahmud ◽  
Ahmad Lotfi
Keyword(s):  
Machine Learning ◽  
Open Access ◽  
Short Term Memory ◽  
The Body ◽  
Data Sets ◽  
Additional Information ◽  
Machine Learning Model ◽  
Signal Characteristics ◽  
Wide Range ◽  
Memory Network

AbstractAcquisition of neuronal signals involves a wide range of devices with specific electrical properties. Combined with other physiological sources within the body, the signals sensed by the devices are often distorted. Sometimes these distortions are visually identifiable, other times, they overlay with the signal characteristics making them very difficult to detect. To remove these distortions, the recordings are visually inspected and manually processed. However, this manual annotation process is time-consuming and automatic computational methods are needed to identify and remove these artefacts. Most of the existing artefact removal approaches rely on additional information from other recorded channels and fail when global artefacts are present or the affected channels constitute the majority of the recording system. Addressing this issue, this paper reports a novel channel-independent machine learning model to accurately identify and replace the artefactual segments present in the signals. Discarding these artifactual segments by the existing approaches causes discontinuities in the reproduced signals which may introduce errors in subsequent analyses. To avoid this, the proposed method predicts multiple values of the artefactual region using long–short term memory network to recreate the temporal and spectral properties of the recorded signal. The method has been tested on two open-access data sets and incorporated into the open-access SANTIA (SigMate Advanced: a Novel Tool for Identification of Artefacts in Neuronal Signals) toolbox for community use.

scholarly journals A study into the scale effect on the strength properties of polymer composite materials

2019 ◽  
Vol 5 (2) ◽  
pp. 103-108
Author(s):  
Valentina V. Kiryushina ◽  
Yuliya Yu. Kovaleva ◽  
Petr A. Stepanov ◽  
Pavel V. Kovalenko
Keyword(s):  
Composite Materials ◽  
Polymer Composite ◽  
Scale Effect ◽  
Mechanical Characteristics ◽  
Full Scale ◽  
Sample Thickness ◽  
Polymer Composite Materials ◽  
Test Machine ◽  
Test Results ◽  
Laboratory Sample

Polymer composite materials (PCM) are used extensively and are viewed as candidates for application in various industries, including nuclear power. Despite a variety of methods and procedures employed to investigate the mechanical characteristics of PCMs, the use of the laboratory sample mechanical test results to design and model large-sized structures is not always fully correct and reasonable. In particular, one of the problems is concerned with taking into account the scale parameter effects on the PCM strength and elastic characteristics immediately in the product. The purpose of the study is to investigate the scale effects on the mechanical characteristics of glass reinforced plastics using phenolformaldehyde and silicon-organic binders and a fabric quartz filler. Samples of four different standard sizes under GOST 25604-82 and GOST 4648-2014 were tested for three-point bending using an LFM-100 test machine to estimate the scale effect. The thicknesses of the model samples were chosen with regard for the wall thicknesses of full-scale products under development or manufactured commercially and the test machine features, and varied in the limits of 1.6 to 7.5 mm. The tests showed that strength decreased as the sample thickness was increased to 3 mm and more both at room and elevated (200 to 500 °C) temperatures, which can be described by an exponential function based on the Weibull statistical model. The values of the Weibull modulus that characterizes the extent of the scale effect on the strength of the tested materials were 4.6 to 6.7. The average bend strength in the sample thickness range of 3 mm and less does not vary notably or tends to increase slightly as the thickness is increased. This fact makes it possible to conclude that estimation of allowable stresses in a thin-wall product requires the use of test results for samples with a thickness that is equal to the product wall thickness since standard samples may yield overestimated allowable stress values and lead, accordingly, to incorrect calculations of the strength factor. The results obtained shall be taken into account when defining the allowable levels of operation for full-scale products and structures of polymer composites based on the laboratory sample strength data as well as when estimating their robustness as a characteristic of the product’s fail-safe operation.

Failure tests on full-scale models of grout laminated wood decks

2004 ◽  
Vol 31 (1) ◽  
pp. 133-145 ◽  
Author(s):  
Aftab A Mufti ◽  
Baidar Bakht ◽  
Dagmar Svecova ◽  
Vidyadhar Limaye
Keyword(s):  
Load Distribution ◽  
Full Scale ◽  
Bottom Surface ◽  
Distribution Characteristics ◽  
Flat Bottom ◽  
The Third ◽  
Scale Models ◽  
Lower Load ◽  
Load Tests ◽  
The University

Grout laminated wood decks (GLWDs), representing the third generation of stressed wood decks, comprise either laminates or logs trimmed to obtain two parallel faces. The logs or laminates, running along the span, are held together by means of transverse internal grout cylinders that may be in either compression or tension. Two full-scale models of GLWD were constructed at Dalhousie University, Halifax, one with grout cylinders in compression and the other with the cylinders in tension. Service load tests conducted in Halifax showed that the former deck had better load distribution characteristics. Two years after the tests in Halifax, the models were shipped to The University of Manitoba in Winnipeg, where they were tested to failure under a central patch load. Because of miscommunication with the supplier, the logs of the GLWD with grout cylinders in compression were also trimmed to the third face that was kept at the bottom of the deck. The failure tests showed that despite its superior load distribution characteristics, the deck with grout cylinders in compression failed at a significantly lower load than the GLWD with cylinders in tension. It is argued that a planar surface in the logs at the flexural tension face not only reduces their flexural stiffness but also brings the defects of wood to the surface with maximum stress. The deck with the flat bottom surface underwent tension failure of the most heavily loaded logs, whereas the deck with the intact round surface of the logs at both top and bottom failed by horizontal splitting of all the logs.Key words: articulated plate, bridge deck, grout laminated deck, orthotropic plate, timber.

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