Yerzley oscillograph

The Yerzley oscillograph is specified in ASTM D94519 and is shown schematically in Figure 9.7. It consists of a horizontal beam pivoted so as to oscillate vertically and in so doing deform the test piece mounted between the beam and a fixed support. A pen attached to one end of the beam records the decaying train of oscillations on a revolving drum chart. The dynamic deformation of the test piece can be superimposed on a static strain and the mode of deformation can be either shear or compression. The mass and, hence, the inertia of the beam can be varied by attached weights. 

Figure 9-7. Yerzley oscillograph, (a) Apparatus (b) trace of decaying wave train...

The Yerzley Oscillograph (ASTM D945) has been used for rubber testing by monitoring the decay of the sample subjected to a dynamic oscillation by a cantilever. Terms such as Yerzley hysteresis and resilience seem peculiar to this apparatus, and since large deformations were necessary, the nonlinearity suggests that only an average modulus could be obtained. 

Resilience is measured by using one of several methods including the rebound pendulum test (for example, ASTM D 1054), the vertical rehound test (ASTM D 2632), or the Yerzley oscillograph test (ASTM D 945). 

For rapid determination of the tan 6 at low frequencies and room temperature of the large number of rubber vulcanizates tested, we adapted the Yerzley Oscillograph. This equipment was one of the earliest instruments used for determining the dynamic mechanical properties of rubber vulcanizates. 

The tan 6 measured by our Instrumented Yerzley Oscillograph (abbreviated as lYO) has adequate precision, and was found to correlate reasonably well with tan 6 measured on rubber samples by the MTS equipment at 40 Hz and 60 C. It also correlates remarkably well with rolling resistance of tires (Figure 11) as determined by the "Twin Roll Method" and used for evaluation and testing of tires. 

Bashore resilience Yerzley oscillograph Torsional rigidity Heat Build-up Oven aging Solvent Resistance... 

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