Dynamic durability tests

In conclusion, noble metals deposited on ceria-zirconia supports show both increased OSC and increased activity for NOx conversion, the clearer effect being obtained in dynamic conditions [102]. They are also more resistant than pure ceria to thermal sintering, since they are able to maintain a good activity even in a lOOO C durability test [102]. 

The beams, fabricated in the material testing laboratory, having dimensions of 7.5 cm x 7.5 cm X 30 cm were tested for relative dynamic modulus in accordance with ASTM C 666-97. Three-inch cubes were sawn from each of the beams after the relative dynamic modulus test. The cubes were tested using procedures presented in ASTM C 116-90, Test Method for Compressive Strength of Concrete Using Portions of Beams Broken in Flexure. When the specimens were 28 days old, the freeze-thaw durability specimens were cured in lime-saturated water until testing was begun. 

The durability of a flexible foam may be determined by using a shear or a pounding force on the foam. Tests described here are designed to assess the suitability of foam for use in upholstery and are therefore primarily aimed at cellular latex or polyether urethane types of foam. A dynamic fatigue test using a roller shear at constant force is described in ASTM D 3574, Test U. However a much more popular fatigue test for cellular upholstery materials is determined by constant load pounding. 

Statistical sampling of tires for durability testing, uniformity, and dynamic balancing this testing includes many of the development tests reviewed earlier such as conicity, radial runout, and lateral force variation. 

As with common paving bitumens, the tests conducted on hard paving bitumens aim at determining their consistency at intermediate service temperatures (penetration test) and at elevated service temperatures (softening point and dynamic viscosity test) and their durability (resistance to hardening test). Kinematic viscosity, Fraass breaking point, flash point and solubility are also properties considered useful in the specification of hard paving bitumens. 

Tapered double cantilever beam This is again mode I, but the value of dClda can be made constant by tapering of the arms of the specimen (see Fig. 2b). Thus, Gj is independent of crack length and this design is well suited to tests where the value of a is difficult to measure, for example, environmental tests (see Durability fundamentals) and dynamic fatigue tests. This is also used in ASTM D 3433. The value of Gic is given by... 

Finally, the apparent normalized release rate of Si (r(Si)norm) in the HT samples was compared to the one obtained for the standard HLW glass SON68 under the same conditions of corrosion. Of the 23 HT samples tested, 6 samples exhibit r(Si)norm < SON68, thus presenting a highly favourable dynamic picture with respect to their long-term durability. 

Several other tests are used to correlate properties with the working conditions. The dynamic mechanical analyzer (DMA) is used to measure modulus and viscoelastic properties related to ductility. By using the DMA test method, the degradation in modulus could be imderstood and applied to the end use application. The effect of the environmental conditions is also tested the esthetic durability in heated environments is not restricted to warp and relaxation attributed to creep. Creep and stress relaxation tests are also done on SMC/BMC for their structural applications. The retention of color is critical for a heated appliance application. BMC/SMC can be formulated to offer excellent color stability when exposed to high temperatures. 

Chapters 6 and 7 refer to two practical case studies, in particular two fuel cell propulsion systems of different size. Here the technical characteristics of all individual components are described, and the results of an experimental characterization carried out on laboratory dynamic test benches are discussed. The findings of these two chapters evidence the limitations and potentialities of fuel cell power trains at the present state of development, in terms of performance, efficiency, environmental impact and durability. 

ABSTRACT This research project aims to use reactive powder concrete, RPC. as a new repair material and evaluate its bond strength and bond durability to existing concrete. One accelerated aging environment, namely a freeze-thaw cycle acceleration deterioration test, was selected for the evaluation of bond durability of the repair materials. Before and after aging, the samples were evaluated by the compressive strength, bond strength (slant shear test), steel pull out strength, and relative dynamic modulus NDT tests. 

The test results show that the RPC possesses high bond strength, dynamic modulus, and bond durability as compared with other concretes. The adhesion between the RPC and the steel is also much greater than that for the other concretes. It would be interesting to verify the consequences of this improved adhesion in reinforced concrete structures. 

P(2) Testing shall consist of loading the connection, either statically or dynamically, to determine its mechanical properties and/or behaviour. Alternatively the effects of environmental loads, such as temperature cycling or a corrosive atmosphere, may be used to determine the durability of the connection. 

Liu, D. and Case, S. (2006) Durability study of proton exchange membrane fuel cells under dynamic testing conditions with cyclic current profile. J. Power Sources, 162, 521-531. 

The application of these principles to an actual adhesively bonded joint is anything but straightforward. One problem is the lack of pertinent information on the performance of adhesive joints. Most test data generated by adhesive producers are only useful for comparison purposes and are of limited use to the design engineer. Also, there is only limited information available on the performance of bonded joints exposed to service environments, while subjected to static or dynamic stresses. Adequate adhesive characterization and prediction of joint durability remain goals for the future. 

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