Performance test methods composites

Data for thermal movement of various bitumens and felts and for composite membranes have been given (1). These describe the development of a thermal shock factor based on strength factors and the linear thermal expansion coefficient. Tensile and flexural fatigue tests on roofing membranes were taken at 21 and 18°C, and performance criteria were recommended. A study of four types of fluid-appHed roofing membranes under cycHc conditions showed that they could not withstand movements of <1.0 mm over joiats. The limitations of present test methods for new roofing materials, such as prefabricated polymeric and elastomeric sheets and Hquid-appHed membranes, have also been described (1). For evaluation, both laboratory and field work are needed. 

An extensive survey of accelerated test methods for anticorrosive coating performance which emphasizes the need to develop more meaningful methods of testing has been pubUshed (129). The most powerful tool available is the accumulated material in data banks correlating substrate, composition, apphcation conditions, and specifics of exposure environments with performance. 

CFR Part 60 (Appendix A) New source performance standards Methods 1-4 Test location, volumetric flow rate, gas composition, moisture content... 

There may also be a need to consider the performance of pre-corroded test specimens. Apart from the fact that these conditions frequently arise in service it is also important for two other reasons. First, the presence of corrosion products or other surface layers may affect the access of constituents of the environment to the underlying metal surface-where the corrosion process occurs —and, second, in the case of alloys some pre-corrosion may lead to compositional changes in the surface. These factors should be taken into account in the application of any test method. 

Finally, one aspect that can pay a role in compositional studies is the sieve (screening) analysis. Like all petroleum products, sampling is, or can be, a major issue. If not performed correctly and poor sampling is the result, erroneous and very misleading data can be produced by the analytical method of choice. For this reason, reference is made to standard procedures such as the Standard Practice for Collection and Preparation of Coke Samples for Laboratory Analysis (ASTM D346) and the Standards Test Method for the Sieve Analysis of Coke (ASTM D293). 

In a search for reliable accelerated test methods for determining coating performance, electrochemical techniques have often been explored. The corrosion resistance of a coated steel panel is a composite of the steel quality, its surface finish and the quality of the coating. For this reason. Bonderite 40 coated steel panels were included in our work. They were employed primarily to aid in the interpretation of the electrical measurements for the nitrile-based photocured samples. 

In order to identify and solve a fuel problem, it is usually necessary to collect information about the physical and chemical properties of the fuel. A variety of test methods are available for this purpose. Outlined below are some of the primary testing methods which are commonly used to evaluate the composition and performance of fuels. 

The standard ASTM D2585 filament wound pressurized bottle test method utilizes a 0.15-m (5.75-in.)intemal diameter filament wound bottle as the test article. This standard test method (with variation in bottle sizes) has been used extensively by the rocket motor industry [47-50] to evaluate glass, aramid, and graphite fiber composite vessel performance. This test method has generally shown good results, but is a relatively expensive test method. Testing of one 0.5-m (20-in.) diameter bottle can cost up to 20K. Other disadvantages are ... 

U.S. Bureau of Mines (BoM) Impact Apparatus Method T 505.1, Department of Defense, USA. (b) Department of Defense (1987) MIL-STD-650, Explosives Research Laboratory (ERL) Type 12 Apparatus Method T 511.1, Department of Defense, USA. (c) Kohler, J., and Meyer, R. (1993) Explosives, 4th edn, Wiley-VCH Verlag GmbH, Weinheim, Germany. (d) McIntyre, L. (1980) A Compilation of Hazard and Test Data for Pyrotechnic Compositions. Contract Report No. ARLCD-CR-80047, US Army Armament Research and Development Command, Dover, NJ. (e) US Naval Weapons Center (1972) Safety and Performance Tests for Qualification of Explosives, NAVORD OD-44811, Naval Weapons Center, China Lake, CA, USA. ... 

Evaluating composite performance requires test methods for mechanical properties of the constituent materials (fibers, tows, filaments, and matrices) as well as the composite materials themselves. The types and quantities of tests to be performed, and the selection of testing parameters, depends on the information desired. For material development, the tests may be much simpler and less numerous than those that would be chosen for design qualification, but may encompass a greater range of test parameters than would be expected in service. In the case of materials development, it is the trends in the data and the mechanisms by which failures occur which are most important, and it is crucial to examine the extremes of behavior. For component design and qualification, it is more important to know the reliability and reproducibility of the material under conditions which resemble the expected service conditions. 

The performance of a flexible PVC compound is often defined by its plasticiser content and composition and a simple, accurate and fast method of plasticiser identification could, therefore, be an effective quality control and benchmark performance test in new product development studies. Gas chromatography was shown to provide the most effective identification method and it was demonstrated that it could be complemented by IR spectroscopy, liquid chromatography and physical observations to confirm identity. 4 refs. 

Trichlorosilane DPR from the Dow Coming Midland Plant was analyzed for composition, flash point, pyrophoricity, etc. New test methods were developed to quantify the shock-sensitive nature of the hydrolyzed gels which commonly form when handling this stream. This testing was performed on individual fractionated DPR species, and the hazards of each component were quantified. It was determined that SiH-containing chlorosiloxanes had played a key role in several past safety incidents. 

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