Dynamic Compression Property of Vulcanized Rubber

To reduce undesirable vibration effects, the source may be isolated by means of vibration absorbers. The answer to the isolation problan is the correct mounting of the source (machine) on springs and dampers, that is, on rubber blocks [14], Because dynamic properties are of great concern in engineering applications, including springs and dampers, dynamic tests are much more useful than the simple static tests. As said above, there are two classes of dynamic motions free vibration and forced vibration. 

In the following example [15], a forced vibration test is chosen in which the oscillation frequency is maintained away from resonance. 

The rubber material is obtained by curing a scrap rubber powder at various times and temperatures, and the various values of the state of cure are calculated from the partial heat evolved from the cure reaction measured by calorimetry, as already shown in Chapter 4. The dynamic properties in compression are determined at room temperature by using several samples for which the state of cure is ranging from 36 to 90%. The apparatus used enables the measurement of the visco-elasticity of the rubber sample under various conditions such as compression, traction, shear (vis-coelasticimeter from Metravib, France). 

FIGURE 6.7 In-phase modulus in dynamic compression as a function of the state of cure, SOC, of the samples, for different values of the frequency. 

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