Tensile strength, measurement

Practical considerations enter into the experimental plan in various other ways. In many programs, variables are introduced at different operational levels. For example, in evaluating the effect of alloy composition, oven temperature, and varnish coat on tensile strength, it may be convenient to make a number of master alloys with each composition, spHt the alloys into separate parts to be subjected to different heat treatments, and then cut the treated samples into subsamples to which different coatings are appHed. Tensile strength measurements are then obtained on all coated subsamples. 

Figure 6.2 displays experimental data concerning tensile strengths measured on dry samples (0% RH) and on samples stored in 50% RH air.The continuous lines are modelled tensile strengths. 

Figure 7 Comparison of power consumption and tensile strength measurements.

Betz G, Junker Biirgin P, Leuenberger H. Power consumption profile analysis and tensile strength measurements during moist agglomeration process. Int J Pharm 2003 252 11-25. 

Figure 2. Tensile strength measurement with the Instron Universal Testing machine...

As shown in Figure 1, these transition points were superimposed on the tensile strength/temperature curve, and the author suggested that they can supplant such tedious tensile strength measurements. 

Betz, G., Bu-gin, P.J., and Leuenberger, H., Power consumption pro le analysis and tensile strength measurements during moist agglomeratiraiti, J. Pharm., 252, 11-25 (2003a). 

The fibers are highly crystalline and single crystal tensile strength measurements range from 2 10s psi to 1 106 psi, while the modulus of elasticity ranges from 10 106 psi to 26 10 psi. These values are comparable to the published values for chrysotile asbestos. 

In general tensile strength is not used alone to predict flow. Danjo et al. utilized tensile strength measurement, shear cell measurement, and Carr s flow factor to investigate the effect of particle shape on powder flow. 

In summary, various shear and tensile strength measuring devices have been developed, and many are commercially available. Though they are more complex and often more difficult to use than the other methods, they yield data on a more scientific basis, which allows a mechanistic approach to flow problems. 

The oriented film specimens were mounted on aluminum frames and exposed on an Atlas Weather-Ometer, Model 65WR. An 18 minute spray cycle together with an 102 minute cycle at 55% relative humidity and approximately 65°C was used. At regular intervals, the test specimens were removed from exposure and their tensile strength measured on an Instron Model 1102. A decrease in tensile strength, expressed as tenacity, over the tensile strength of the same formulation before exposure, is a measure of the deterioration of the physical properties of the polymer. "Failure" in this test is defined as a loss of 50% or more of the initial sample tenacity. 

Ecker (232) has shown that laboratory abrasion loss data may be related to tensile strength measured at 100° C and e= 150 sec-1. The resulting plot is a band of experimental points, the width of which along the abrasion loss axis nowhere exceeds + 20% from its center. To obtain closer correlation it is necessary to consider also the coefficient of friction and the viscoelastic properties of the rubber (232). Sliding friction and viscoelasticity in rubbers are closely related (233). 

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