Rebound tests

Falling-ball rebound test, 244 Ferrocene-containing polybenzimidazole, 315... 

Resilience is one of the most common rebound tests. It is fundamentally a deformation of the material for half a cycle. The rebound resilience basically is the ratio of the indentor after to before impact expressed as a percentage. There are a large number of methods for this test, including the following. 

Fig. 3. Rebound test on steel placed on a flat rigid surface recorded force F,(0-) and linear fit to the initial part of P, (—).

As ball tests are impossible on thin sheet, rebound tests were made, using the Shore apparatus, on sheets of the thin series, possessing respectively 50 %, 100 %, and 300 % cold work. 

Martin et al. (1975) has given procedures to evaluate these two parameters from the results of static rebound tests in a consolidation ring and cyclic load tests on dry sand, respectively. Finn and Bhatia (1981) has also reported good agreement between predicted and measured values using the proposed method. 

Dynamic Rebound Test Scleroscope. in this test, the rebound of a diamond-tipped weight dropped from a fixed height is measured (34). There are two models of the instrument Model C (HSc) uses a hammer of small mass ( 2.3 g) and a large height of fall (ss251 mm) Model D (HSd) uses a hammer of about 36 g and a short fall (ssl8 mm). 

The Rebound Test, a test easily adapted to measurements over wide temperature ranges whereby a ball is bounced on the sample surface and the height of the rebound is taken as a measure of hardness. (Shore s name is sometimes associated with this measure of hardness.)... 

The fractional return, to an impacting hody, of the energy with which it strikes a resilient test specimen. ASTM D 1054 details a pendulum-rehound test, while D 2632 and D 3574 describe drop-weight-rebound tests, all employing this principle and all in section 09.01. 

E values were determined by a rebound test performed on unnotched specimens at low impact speed (0.2-0.3 m/s) using the same instrumented pendulum apparatus. 

This test, also known as the ball rebound test, is very useful in evaluating the resilience of foams. The test consists of dropping a steel ball onto a foam specimen and noting the height of rebound. The apparatus, as shown in Figure 14-9, consists... 

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