Confusion in the evaluation of sound barriers under harmonized standard

2021 ◽  
Vol 263 (4) ◽  
pp. 2318-2326
Author(s):  
Pavel Rubáš
Keyword(s):  
Decision Rules ◽  
Test Method ◽  
Sound Insulation ◽  
Guidance Document ◽  
Current Standard ◽  
Noise Barriers ◽  
Testing Procedures ◽  
Test Standards ◽  
Sound Barriers ◽  
Single Number

After the obligatory introduction of the declaration of uncertainty in EN 1793-2:2018, the B categories shall not be used to prevent further confusion. Contrary to the updated standard, B categories remain a ubiquitous contractual criterion in the Czech Republic. Contractors continue to request insulation category B3 products determined according to the cancelled EN 1793-2:1997. The current standard only specifies a test method for determining the intrinsic airborne sound insulation performance of noise barriers designed for tunnel roads, deep trenches or covered spaces. EN 1793-6:2018 shall be used for barriers designed for non-reverberant conditions. Notified bodies involved in barriers testing should exercise care and analyze whether supporting test standards in the cancelled but still harmonized EN 14388:2005 can be used or whether the latest testing procedures will be considered. A guidance document is vital because the situation is becoming increasingly confusing. Common rules should be established across the EU to prevent invalid contractual requirements concerning B3 category barriers designed for non-reverberant conditions. The paper analyzes the current unsatisfactory situation, discusses the application of single number rating involving uncertainties, and proposes decision rules for logical and illogical contractual requirements.

scholarly journals Low-cost test setup for motorcycle protective clothing abrasion examination

2021 ◽  
Vol 2 (2) ◽  
pp. 196-207
Author(s):  
Dietrich Spädt ◽  
Imane Moulefera ◽  
Al Mamun ◽  
Marah Trabelsi ◽  
Lilia Sabantina
Keyword(s):  
Abrasion Resistance ◽  
Protective Clothing ◽  
Low Cost ◽  
Good Alternative ◽  
Test Method ◽  
Road Accidents ◽  
Testing Procedures ◽  
Test Standards ◽  
Physical Injuries ◽  
Different Types

The personal protective equipment and protective clothing for motorcyclists reduce physical injuries to victims of road accidents. Therefore, it is important that the protective clothing complies with a number of test standards, which must be taken into account during the manufacturing process. However, the EN17092-1 to 6 standard does not necessarily correspond to a real accident situations and these testing procedures are time consuming. In this study, a simple and inexpensive self-constructed device for testing the abrasion resistance of motorcycle protective clothing was developed and evaluated. Different types of textiles and leather with and without coating were tested and compared. According to the results of this study, not only leather but also textiles offer good abrasion resistance results. The results show that the strength of an impact significantly changes the abrasion resistance. The developed test method can provide a good alternative as a low-cost and simple test method of abrasion resistance of motorcycle protective clothing.

On the Construction of Analytical Cooling Curves from ASTM D6200 Data Using Multi-Variable Gradient Descent Method

2021 ◽  
Author(s):  
James Jan ◽  
D. Scott MacKenzie
Keyword(s):  
Cooling Rate ◽  
Oil Quality ◽  
Standard Test ◽  
Descent Method ◽  
Test Method ◽  
Cooling Curve ◽  
Gradient Descent Method ◽  
Mathematical Function ◽  
Current Standard ◽  
Characteristic Points

Abstract ASTM D6200 is a standard test method to evaluate cooling characteristics of quench oils. The test produces six discrete numbers representing the cooling characteristics: three temporal scales (time to cool to 600°C, 400°C, and 200°C), two cooling rates (max cooling rate and cooling rate at 300°C), and one temperature scale (at max cooling rate). One of the main purposes of ASTM D6200 is to monitor the oil quality to ensure gears are properly quenched. The current standard only includes specifications for gear quenching oil and its applications are limited to physical testing. The intent of this research is to explore the possibility of broadening the support for more quenchants and extending applications to virtual engineering. This research includes two parts. The first part is the development of a systematic method to identify the characteristic points of a cooling curve. The second part is the construction of an analytical cooling curve based on the characteristic points. The analytical cooling curve is a mathematical function of temperature versus time that can provide temperature at any given time in the quenching process. In addition, the curve is differentiable to provide the cooling rate information at any given time as well.

The Analysis and Assessment of Test Method for Flammability of an Automotive Headlining Fabric

2011 ◽  
Vol 332-334 ◽  
pp. 1162-1166
Author(s):  
Zhuo Zhang ◽  
Ying Qing Liu ◽  
Zhong Hai Ren ◽  
Jia Zhuang Ma ◽  
Hu Shui Ye
Keyword(s):  
Traffic Safety ◽  
Test Method ◽  
Highway Traffic ◽  
National Highway Traffic Safety ◽  
Test Standards ◽  
Foreign Countries ◽  
Mandatory Standard ◽  
Testing Standards ◽  
Interior Textile ◽  
Automotive Interior

The flammability is one of the most important features about safety for automotive interior material. This paper summarized the testing standards for flammability performed testing on a type of interior textile material made by one of domestic manufacturers, in accordance with the Chart 571.302 Standard No. 302 of the National Highway Traffic Safety Administration of U.S. The complete introduction of national mandatory standard of China in flammability of interior material was introduced and domestic test standards of flammability with those of foreign countries all over world were compared. Finally, this paper proposed possible and would-be necessary parameters based on comprehensiveness of this kind of test due to safer requirement in future.

Empirical study on the correlation between measurement methods under diffuse and direct sound field conditions for determining sound absorption and airborne sound insulation properties of noise barriers

2021 ◽  
Vol 263 (3) ◽  
pp. 3350-3361
Author(s):  
Andreas Fuchs ◽  
Reinhard Wehr ◽  
Marco Conter
Keyword(s):  
Empirical Study ◽  
Sound Absorption ◽  
Sound Field ◽  
Research Programme ◽  
Measurement Methods ◽  
Field Conditions ◽  
Acoustic Properties ◽  
Sound Insulation ◽  
Noise Barriers ◽  
Airborne Sound

In the frame of the SOPRANOISE project (funded by CEDR in the Transnational Road Research Programme 2018) the database of the European noise barrier market developed during the QUIESST project was updated with newly acquired data. This database gives the opportunity for an empirical study on the correlation between the different measurement methods for the acoustic properties of noise barriers (according to the EN 1793 series) to further investigate the interrelationships between these methods by using single-number ratings and third-octave band data. First a correlation of the measurement methods for sound absorption under diffuse field conditions (EN 1793-1) and sound reflection under direct sound field conditions (EN 1793-5) is presented. Secondly, a correlation of the measurement methods for airborne sound insulation under diffuse field conditions (EN 1793-2) and airborne sound insulation under direct sound field conditions (EN 1793-6) is shown. While for airborne sound insulation a distinct correlation is found due to the wide data range, for sound absorption no robust correlation can be found.

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