Dynamic Mechanical Analysis part 11 pps

... tells us the maximum total force and the maximum from the dynamic stress–strain run tells us the maximum dynamic force. Then, we pick a dynamic force strong enough to give us a strain between 2–12 ... specimens as in the static stress–strain experiment above, run a dynamic stress scan using tension control set to 110 % and a dynamic ramp rate of 95 mN/min. Compare the results with...

Ngày tải lên: 05/08/2014, 09:19

... Tests 3.10 Thermomechanical Analysis Notes Chapter 4 Dynamic Testing 4.1 Applying a Dynamic Stress to a Sample ©1999 CRC Press LLC dynamic measurements were an integral part of polymer ... an introductory book on dynamic mechanical analysis. This book attempts to give the chemist, engineer, or material scientist a starting point to understand where and how dynamic m...

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... to magnify the differences between materials as well as predict long-term performance (Figure 1 .11) . Repeated cycles of creep–recovery show how the product will wear in the real world, and the ... response of the fibers is greatly affected by the solution it is tested in. Similar tests in both dynamic and static modes are used in the medical, automotive, and cosmetic industries. The adapta...

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... time. In Figure 3.6a, we show the relationship of the resultant strain curve to the parts of the four-element model. This analysis is valid for materials in their linear vis- coelastic region and only ... find polymer manufacturers with a room full of parts under load that are being watched. This checks not only the polymer but also the design of the part. More accurately representative sa...

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... data as used to determine the T g (Figure 3.11b). Since many materials are used in contact with a dissimilar material FIGURE 3.10 Thermomechanical analysis test methods in common use. Dilatometry allows ... it is heated (Figure 3.11a). Seen as an inflection or bend in the thermal expansion curve, this change in the TMA can be seen to cover a range of temperatures (Figure 3.11b), of which th...

Ngày tải lên: 05/08/2014, 09:19

... only plot dynamic stress vs. dynamic strain, but also get E¢, E≤, E*, tan d, h*, and other dynamic properties for each cycle. This allows us to plot those properties as a function of dynamic stress ... in Figure 4.11a. Note that the important dimensions are the same as ©1999 CRC Press LLC FIGURE 4.15 Results from dynamic stress–strain curves showing (a) the relationship between dyn...

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... but they are normally too weak or too broad for determination by these methods. DMA, Dielectric Analysis (DEA), and similar techniques are usually required. 19 Some authors have also called ... T b compared to the T g for a high-impact and low-impact nylon. It has been shown, particularly in cured thermosets, that increased freedom of movement in side chains increases the...

Ngày tải lên: 05/08/2014, 09:19

... Measurement of Viscoelastic Properties by Dynamic Mechanical Analysis, Masters thesis, Univer- sity of Texas at Austin, 1994. R. Hagan, Polymer Testing, 13, 113 , 1994. 3. S. Goodkowski and B. Twombly, ... Chapter 7. Sometimes the polymer is added as a binder to an inorganic material, like the magnetic particles used to make the magnetic coating on a videotape. This is then coated on a...

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... This is also done with thin films and adhesive coatings. A sample cure profile for a commercial two -part epoxy resin is shown in Figure 6.6. From this scan, we can determine the minimum viscosity ... gives the viscosities of common materials. As we shall see below, the post-cure is often a vital part of the curing process. The cure profile is both a good predictor of performance as well as a...

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... sufficient flow under pressure at low frequency to fill the pores of the material to obtain a good mechanical bond. When the laminate is later subjected to peel, we want the material to be very elastic ... method and added to the data collected by frequency scans. However, as creep is not the same as dynamic tests, sometimes the data are not even similar GN¢== ÆÆ Æ () () ()wwggyg wg g 2 0 1...

Ngày tải lên: 05/08/2014, 09:19