And d Impact-friction pendulum

Ammonium Nitrate Explosives, Tests of Spencer Chemical Co [a)Cook-off temperature b)Detonation velocity c)Waxrgap and d)Impact-friction pendulum]... 

Impact-Friction Pendulum Test (p XVII) and p A354, Note d... 

The most frequently applied impact tests are shown in Fig. 24.17 A and B. A pendulum (shown as a filled arrow) falls from a certain height the loss in the potential energy of the pendulum is assumed equal (with a correction for losses such as friction) to the energy Uo absorbed by the specimen see Eq. (24.1). The Charpy test is described by the ASTM D 256 standard method B, the Izod test by the same standard method A. We see (Fig. 24.17 A) that in the Charpy test there is a symmetry with respect to the center of the specimen. By contrast, in the Izod test (Fig. 24.17 B) the bottom half of the specimen remains untouched while the top part is broken off. We—and more and more laboratories around the world— perform now both tests with a sensor installed on the pendulum and connected to a computer. Thus, not only a single value of the energy but a whole curve is obtained. For convenience single values of impact strength (IS) for a number of polymers are listed in Tables at the end of this chapter. 

---