Test rates

Factory Mutual provides loss prevention data sheets that explain how to protect buildings from wind damage. Pressure coefficients that define increased uplift at corners and edges adjust the calculated uplift pressures. A laboratory uplift pressure test rates roofing assemblies. An uplift pressure of 2.9 kPa (0.42 psi) must be withstood under FM conditions to meet the Class 1-60 requirements. The FM approval guide is revised aimuaHy (37). 

Although sealant manufacturer s Hterature commonly reports modulus values, these values must be interpreted carefully. Specimen sizes, test rate, cure conditions, and the time a sealant has been allowed to cure when tested can all have a significant effect on modulus. Therefore, for a tme comparison, sealants should be evaluated by a standard test that examines all sealants by the same procedure. In general, the longer a sealant has been allowed to cure, the more reaUstic the modulus data. 

Figure 10.5. Effect of polymer density, testing rate and temperature on the shape of the stress-strain...

As might be expected of a somewhat polar thermoplastics material, mechanical, electrical and other properties are strongly dependent on temperature, testing rate and humidity. Detailed data on the influence of these Vciriables have been made available by at least one manufacturer and the following remarks are intended only as an illustration of the effects rather than as an attempt at providing complete data. 

The figures given in the table are obtained on mouldings relatively free from orientation and tested under closely controlled conditions of temperature, testing rate, and humidity. Changes in these conditions or the use of additives may profoundly affect these properties. Details of the influence of these factors on mechanical properties have been published in the trade literature but Figures 18.11-18.14 have been included to illustrate some salient features. 

After the rates have been determined at a series of reactant concentrations, the differential method of testing rate equations is applied. Smith [3] and Carberry [4] have adequately reviewed the designs of heterogeneous catalytic reactors. The following examples review design problems in a plug flow reactor with a homogeneous phase. 

You ll Want to Know NBS Tests Rate Steel Pipe Smoother, Heating/Piping/Air Conditioning, May 1981. 

It should be noted that although ASTM A262 1986 provides details of test procedures no information is given on typical corrosion rates or acceptable limits for various heat-treated alloys, which are regarded as outside the province of a specification that describes test procedures. Table 19.4, taken from a paper by Brown, shows the maximum acceptable evaluation test rates specified by the Du Pont Company for various alloys tested by the acid... 

Table 19.4 Maximum acceptable evaluation test rates specified by Du Pont for services where susceptible material would be intergranularly attacked ...

Test rate and property The test rate or cross-head rate is the speed at which the movable cross-member of a testing machine moves in relation to the fixed cross-member. The speed of such tests is typically reported in cm/min. (in./min.). An increase in strain rate typically results in an increase yield point and ultimate strength. Figure 2-14 provides examples of the different test rates and temperatures on basic tensile stress-strain behaviors of plastics where (a) is at different testing rates per ASTM D 638 for a polycarbonate, (b) is the effects of tensile test-... 

Fig. 2-14 Examples of using different tensile testing rates.

Correlation with Road Test Ratings of Compounds.718... 

Correlation with Truck Tire Road Test Ratings.753... 

FIGURE 26.38 Correlation and regression coefficients between road test ratings obtained on three different wet road test tracks and laboratory ratings obtained on a wet Alumina 60 laboratory surface as function of... 

However, a correlation with road test ratings can often be improved if an independent term of log V is added to the transformation variable log a-jv. The friction or side force coefficient can then be written as... 

FIGURE 26.40 Correlation coefficient between road test ratings on a wet concrete track and laboratory measurements on a wet blunt Alumina 180 disk. Left as function of log a- v and right as function of log a-rv and log V. 

Relative Ratings of Four Passenger Commercial Tire Tread Compounds for Which Road Test Ratings Were Available as Function of Log Energy and Log Speed... 

Correlation, Regression Coefficients and Intercept of a Linear Relation between the Road Test Ratings from Table 26.4 and the Laboratory Ratings Obtained for Each Cell... 

FIGURE 26.70 Correlation coefficient between road test ratings of three truck tire compounds on re-treaded tires at two different axles and laboratory ratings as function of log energy and log speed. 

FIGURE 26.71 Correlation and regression coefficients between road test ratings of seven truck tire compounds 80 SBR/20 NR differing by type and amount of filler and laboratory abrasion ratings obtained on LAT 100 testing equipment. 

It has already been shown how a correlation between road test ratings and laboratory abrasion can be obtained over a range of energies and speeds (Table 26.6). Usually, a good correlation, i.e., a high correlation coefficient and a regression coefficient near 1 are obtained only over a limited range. 

Correlation between Road Test Ratings and Laboratory Road Test Simulations of a Group of Four Passenger Tires, Discussed Above for Tbeir Laboratory Abrasion and Correlation to Road Test Ratings... 

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