IMPACT TEST METHODS AND RETENTION HARNESS CRITERIA FOR U. S. ARMY AIRCREWMAN PROTECTIVE HEADGEAR

1966 ◽  
Author(s):  
Jr. Haley ◽  
Turnbow Joseph L. ◽  
James W.
Keyword(s):  
Impact Test ◽  
Test Methods

Fasteners at Low Temperatures: Characterization and Methods for Design

2011 ◽  
Author(s):  
Melanie Stephan ◽  
Jens O. Weber ◽  
Ulrich Wuttke ◽  
Christina Berger
Keyword(s):  
Impact Test ◽  
Freezing Point ◽  
Lattice Structure ◽  
Detailed Examination ◽  
Test Methods ◽  
Climatic Conditions ◽  
Test Method ◽  
Design Concepts ◽  
Ductile Behavior ◽  
Pendulum Impact

Bolted joints are a major part of wind energy plants. Due to climatic conditions, they are often exposed to temperatures far below the freezing point. Together with the multiaxial state of stress, which results from the notch effect of the thread, and possible dynamic overloads during operation, sufficient ductility of the material is needed. The state of the art method to investigate the ductile behavior of fasteners is the Charpy pendulum impact test with a V-notched specimen. According to international standard DIN EN ISO 898-1 [1] respectively ASTM F568M-07 [2], fasteners made of carbon steel and alloy steel with a body centered cubic lattice structure can be used for temperatures down to 223 K (−50°C, −58°F) as long as a minimum impact energy of 27 J at 253 K (−20°C, −4°F) is met. As there are several disadvantages in using this test method for fasteners, a detailed examination of existing test methods and design concepts is necessary to find alternatives to the Charpy pendulum impact test. Extensive quasi-static and dynamic material tests were conducted on fasteners with property classes 5.6, 10.9 and 12.9 in a temperature range between 203 K (−70°C, −94°F) and room temperature 293 K (20°C, 68°F). Both mechanical properties and the influence of different specimen geometries were evaluated. Analytical concepts for the description of the low temperature applicability of different steels were analyzed.

Mechanical impact test methods for hard coatings of cutting tools: a review

2021 ◽  
Author(s):  
Tianxiang Wang ◽  
Xuming Zha ◽  
Fengbiao Chen ◽  
Jue Wang ◽  
Yousheng Li ◽  
...  
Keyword(s):  
Impact Test ◽  
Cutting Tools ◽  
Test Methods ◽  
Hard Coatings ◽  
Mechanical Impact

scholarly journals Overview of dynamic test methods for examining the glass window resistance

2021 ◽  
Vol 352 ◽  
pp. 00004
Author(s):  
Richard Jankura ◽  
Vlastimil Mach
Keyword(s):  
Impact Test ◽  
Dynamic Test ◽  
Wind Load ◽  
Test Methods ◽  
Building Structures ◽  
Dynamic Impact ◽  
Window System ◽  
Window Systems ◽  
Extreme Load

In recent years, glass, and glass facades are increasingly used as part of building structures. Due to its functions, glass is used in commercial, residential, or strategic buildings, such as airports, stations, or offices. However, window system is subject to several forms of the load. This can be an extreme load in the form of an explosion, an earthquake, or other types of loads, such as their wind load, or dynamic impact. In the article, we focused on an overview of several norms, standards, and research that address the issue of resilience of window systems. The aim of the article was to identify the parameters that are examined in various tests in the standards. The investigated parameters of windows in a manual attempt at burglary, impact test, and explosion were discussed in the article.

New Fuel for Naval Gas Turbine Engines

1970 ◽  
Author(s):  
G. A. Carlton
Keyword(s):  
Gas Turbine ◽  
Impact Test ◽  
Test Methods ◽  
Turbine Engines ◽  
Gas Turbine Engines ◽  
Fuel Oils ◽  
Methods And Techniques ◽  
Fuel Characteristics ◽  
The Impact

This paper discussed the introduction of a new fuel into the Navy, the impact of this new fuel on gas turbine engines and means being taken by the Navy to evaluate this impact. Test methods and techniques for synthesizing some of the fuel characteristics and a comparison of current U.S. Navy fuel oils are presented.

scholarly journals Variables Affecting the Recovery of Acanthamoeba Trophozoites

Pathogens ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 221
Author(s):  
Monica J. Crary ◽  
Rhonda Walters ◽  
Paul Shannon ◽  
Manal M. Gabriel
Keyword(s):  
Cell Proliferation ◽  
Impact Test ◽  
Storage Conditions ◽  
Test Methods ◽  
Antimicrobial Efficacy ◽  
Recovery Method ◽  
Nutrient Density ◽  
Growth Requirements ◽  
Proliferation Assays ◽  
Recovery Methods

While the results of Acanthamoeba testing have been extensively published, laboratories conducting such testing are left to develop their own methods in the absence of a standardized methodology. The wide disparity of methods has resulted in equally inconsistent reported results for contact lens care (CLC) products. This study’s objective was to determine the source of these discrepancies by evaluating basic Acanthamoeba biology and their impact on antimicrobial efficacy testing, including the ability of a recovery method to stimulate a single trophozoite to proliferate. Antimicrobial efficacy testing was conducted using well-published Acanthamoeba strains, storage conditions, and growth-based recovery methods. To identify variables that influence results, test solutions with low Acanthamoeba disinfection rates were utilized to prevent differences from being masked by high log reductions. In addition, single-cell proliferation assays were executed to understand the growth requirements to stimulate trophozoite propagation in two recovery methods. These studies indicated that both nutrient density (>106 CFU) and the length of plate incubation (at least 14 days) could significantly influence the accurate recovery of trophozoites. Together, this study emphasizes the need to understand how Acanthamoeba trophozoites biology can impact test methods to create divergent results.

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