AYO-IV predicts the mechanical properties of rubber, plastics and other polymers in a small range of deformations. ASTM D 945-16 test method calls for the use of AYO-IV to characterize the mechanical properties such as initial creep, initial set, impact energy, frequency, effective dynamic modulus, point modulus, Yerzley Resilience, and Yerzley hysteresis, Tangent of Delta. These properties are evaluated at deformations of 20% or less for those materials.
The principle of operation of AYO-IV is that of simple harmonic motion: properties of the material under test are derived from the analysis of the vibrational frequency and the damping rate of the free oscillations, which follow the initial known potential energy applied to the test sample. This principle of operation of AYO-IV enables the user to test the specimen at its natural frequency, which is a critical parameter for the design of vibration isolators for their specific applications.