Test methodology for the determination of optimum fusion welding conditions of polyethylene

1989 ◽  
Vol 38 (1) ◽  
pp. 147-162 ◽  
Author(s):  
D. Saint-Royre ◽  
D. Gueugnaut ◽  
D. Reveret
Keyword(s):  
Fusion Welding ◽  
Test Methodology

Determination of Steady-State Adhesive Wear Rate

2005 ◽  
Author(s):  
L. J. Yang
Keyword(s):  
Steady State ◽  
Wear Rate ◽  
Wear Test ◽  
Standard Test ◽  
Test Method ◽  
Testing Time ◽  
Wear Coefficient ◽  
Wear Rates ◽  
Test Methodology

Wear rates obtained from different investigators could vary significantly due to lack of a standard test method. A test methodology is therefore proposed in this paper to enable the steady-state wear rate to be determined more accurately, consistently, and efficiently. The wear test will be divided into four stages: (i) to conduct the transient wear test; (ii) to predict the steady-state wear coefficient with the required sliding distance based on the transient wear data by using Yang’s second wear coefficient equation; (iii) to conduct confirmation runs to obtain the measured steady-state wear coefficient value; and (iv) to convert the steady-state wear coefficient value into a steady-state wear rate. The proposed methodology is supported by wear data obtained previously on aluminium based matrix composite materials. It is capable of giving more accurate steady-state wear coefficient and wear rate values, as well as saving a lot of testing time and labour, by reducing the number of trial runs required to achieve the steady-state wear condition.

A STUDY OF THE IMPACT OF DYNAMIC GROUND ACTIONS ON MOMENTARY VALUES OF FRICTION FORCES AT THE GAS PIPELINE-BACKFILL INTERFACE

Tribologia ◽  
2018 ◽  
Vol 278 (2) ◽  
pp. 21-28
Author(s):  
Wacław GAWĘDZKI ◽  
Dariusz LEPIARCZYK ◽  
Jerzy TARNOWSKI
Keyword(s):  
Heavy Traffic ◽  
Soil Surface ◽  
Test Method ◽  
Limit Values ◽  
Friction Forces ◽  
Test Methodology ◽  
Short Time ◽  
Changes Over Time ◽  
The Impact

Buried pipelines are subjected to the action of static forces and moments caused by friction forces at the pipeline-ground contact. At the same time, pipelines are subjected to dynamic actions generated by paraseismic pulses, in particular, in areas of mining and heavy traffic. The paper presents and experimentally verifies a test method of tribological pipeline-soil interaction in conditions of artificially induced soil static and dynamic actions. The applied test methodology allows the determination of friction forces at the tested pipeline section. The friction forces changes over time on the pipeline and soil surface for the varying pipeline tensioning forces were continuously recorded during the tests. Based on the Short-Time Fourier Transform (STFT) of signals, the paper presents the impact of dynamic actions on momentary values of measured friction forces. Relationships are given that allow the determination of friction forces between the pipeline and the soil, including their limit values resulting in the loss of the mutual adhesion of the pipeline and the soil.

A test methodology for the determination of wear coefficient

Wear ◽  
2005 ◽  
Vol 259 (7-12) ◽  
pp. 1453-1461 ◽  
Author(s):  
L.J. Yang
Keyword(s):  
Wear Coefficient ◽  
Test Methodology

Numerical simulation of welding-induced residual stress in fusion welding process using adaptive volumetric heat source

2014 ◽  
Vol 228 (16) ◽  
pp. 2960-2972 ◽  
Author(s):  
S Singh ◽  
N Yadaiah ◽  
S Bag ◽  
S Pal
Keyword(s):  
Residual Stress ◽  
Numerical Model ◽  
Heat Source ◽  
Measurement Errors ◽  
High Performance ◽  
Welding Process ◽  
Fusion Welding ◽  
Volumetric Heat Source ◽  
Welding Processes

The mechanical properties of a weldment structure are influenced by the level of residual stress generated during fusion welding process. The experimental determination of residual stress is cumbersome and not free from measurement errors. A sophisticated numerical model is relatively easy approach to predict residual stress due to the advancement of high performance computational technology. However, the integration of all process physics to make a sophisticated numerical model is ever demanding. The present work is motivated in that direction and involves a finite element based numerical model for simulation of welding-induced residual stresses. A thermal model using adaptive volumetric heat source has been used to estimate temperature distribution. Subsequently, the thermal history is used to perform stress analysis for butt welded plates using three different fusion welding processes. The material behaviour is assumed as elasto-plastic in nature. The calculated results and their trend have been validated with experimental results available in open literature.

scholarly journals Close-to-Application Test Methodology Validated by a Baseline Study for Novel Bearing Developments in Aircraft Turbines

Lubricants ◽  
2020 ◽  
Vol 8 (1) ◽  
pp. 7
Author(s):  
Philipp Renhart ◽  
Florian Summer ◽  
Florian Grün ◽  
Andreas Eder
Keyword(s):  
Journal Bearings ◽  
Ex Situ ◽  
Experimental Investigations ◽  
Operational Conditions ◽  
New Device ◽  
New Methods ◽  
Test Methodology ◽  
Test Strategies ◽  
Aircraft Application

The main objective of the present paper is the validation of new methods concerning experimental investigations of journal bearings under ordinary and extraordinary operational conditions. Derived results should facilitate the determination of damage mechanisms and a qualitative ranking for a prospective coating development. Prior investigated scenarios like start/stop and emergency running behavior were extended by starved and unlubricated experiments for an aircraft application. Focusing on thermal stability and reproducibility, two new subscale test strategies were developed derived from generalized operational conditions of journal bearings. For an improved ex-situ wear measurement of bearing shells, a new device was developed successfully. The results showed that the newly designed test methodologies are suitable to investigate unlubricated coatings leading to conclusive and repetitive results.

Mechanical and Accelerated Testing of Flip Chip Interconnect Systems

1993 ◽  
Vol 323 ◽  
Author(s):  
Ravi Subrahmanyan
Keyword(s):  
Flip Chip ◽  
Test Methods ◽  
Temperature Cycling ◽  
Accelerated Test ◽  
Solder Interconnects ◽  
Test Methodology ◽  
Low Profile ◽  
Interconnect Systems ◽  
Interconnect System

AbstractFlip chip interconnect systems are becoming increasingly popular in the electronics industry due to their low profile and high densities. During temperature cycles, the differential expansions between various assembly members of a flip chip interconnect system produce mechanical stresses that are the driving force for failures. Such failures can be a significant reliability concern.Accelerated test methodologies for flip chip interconnect systems assess the reliability of existing interconnects and identify potential reliability concerns in future interconnect designs. Traditionally, such methodologies have relied on test methods such as temperature cycling to determine the mechanical integrity of the flip chip interconnect. However, application of such methods to new interconnect materials, geometry and processes requires characterization of basicmechanical behavior of the interconnect system.In this work, the feasibility of using a micromechanical test methodology for flip chip applications is examined. 90PbSn solders is used as an example. The data obtained from such flip chip solder interconnects is validated using a damage integral methodology. The measured data is shown to adequately describe published thermal stress profiles and thermal fatigue life data measured using solder joints of the same composition. Finally, some considerations in the application of micromechanical measurements to determination of acceleration factors and development of accelerated test methods are discussed.

scholarly journals Determination of Microbial Diversity of Aeromonas Strains on the Basis of Multilocus Sequence Typing, Phenotype, and Presence of Putative Virulence Genes

2011 ◽  
Vol 77 (14) ◽  
pp. 4986-5000 ◽  
Author(s):  
Maria Elena Martino ◽  
Luca Fasolato ◽  
Filomena Montemurro ◽  
Marina Rosteghin ◽  
Amedeo Manfrin ◽  
...  
Keyword(s):  
Multilocus Sequence Typing ◽  
Human Infection ◽  
Biochemical Tests ◽  
Web Based ◽  
Content Type ◽  
Test Methodology ◽  
Nonparametric Combination ◽  
Genetic Clusters ◽  
Acylated Homoserine Lactones

ABSTRACTThe genusAeromonashas been described as comprising several species associated with the aquatic environment, which represents their principal reservoir.Aeromonasspp. are commonly isolated from diseased and healthy fish, but the involvement of such bacteria in human infection and gastroenteritis has frequently been reported. The primary challenge in establishing an unequivocal link between theAeromonasgenus and pathogenesis in humans is the extremely complicated taxonomy. With the aim of clarifying taxonomic relationships among the strains and phenotypes, a multilocus sequencing approach was developed and applied to characterize 23 type and reference strains ofAeromonasspp. and a collection of 77 field strains isolated from fish, crustaceans, and mollusks. All strains were also screened for putative determinants of virulence by PCR (ast,ahh1,act,asa1,eno,ascV, andaexT) and the production of acylated homoserine lactones (AHLs). In addition, the phenotypic fingerprinting obtained from 29 biochemical tests was submitted to the nonparametric combination (NPC) test methodology to define the statistical differences among the identified genetic clusters. Multilocus sequence typing (MLST) achieved precise strain genotyping, and the phylogenetic analysis of concatenated sequences delineated the relationship among the taxa belonging to the genusAeromonas, providing a powerful tool for outbreak traceability, host range diffusion, and ecological studies. The NPC test showed the feasibility of phenotypic differentiation among the majority of the MLST clusters by using a selection of tests or the entire biochemical fingerprinting. A Web-based MLST sequence database (http://pubmlst.org/aeromonas) specific for theAeromonasgenus was developed and implemented with all the results.

ASME PTC 46 Performance Tests in Digital Plant Context

2017 ◽  
Author(s):  
Olivier Le Galudec
Keyword(s):  
Performance Test ◽  
Major Change ◽  
Radical Change ◽  
Actual Performance ◽  
Plant Operator ◽  
Test Methodology ◽  
On Line ◽  
Digital Methods ◽  
Definition Of

ASME PTC46 is nowadays a well known widely used Performance Test Code for Plant thermal performances. The Code — originally published in 1996, revised in 2015 — delivers all required guidance and methods for determination of the thermal performances in optimum precision conditions. Present paper considers going a step further in the performance test methodology in the modern context, ie specifically for Plants supported by Digital methods. Although a PTC46 test will deliver valuable information, this information — ie the test result — is valid solely at the point of time of the test on site, after which Plant Operator will not necessarily again have a very sharp vision of the level of Performances. Recent Digital tools and methods are a major change in this context and at present Operators of Digitalised Plants have access to a methodic systematic continuous measurement of the gaps between on-line performances and ideal “as should” status. Availability of such advanced functionalities is now opening the door to a radical change of the guarantees definitions, delivering to Plant developers better inputs without arbitrary assumptions as well as methodic and transparent measurement of the actual performance over significant periods of time, in opposition to the few hours of a PTC46 traditional test. Present paper addresses the possible definition of such new guarantees, as well as updates of the correction approach that are needed in order to make use of the Code principles in the modern Digital context. Pro and cons of both methods are discussed in detail , as well as analogy with other Power Plant areas.

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