Measuring the Dynamic Properties of Elastomers for Analysis

The analysis of small amplitude vibrations in deformed viscoelastic solids (Morman and Nagtegaal (1983), Morman, Kao, Nagtegaal (1981) [4,5] is applicable to rubber support mounts, automotive door seals [3] and vibration isolation gaskets. Use of these capabilities in analysis software such as ABAQUS or MSC.MARC requires the equilibrium large strain material properties and the dynamic material properties. An outline for the experimental determination of these properties at dynamic vibration frequencies between 0.01 Hz. and 20,000 Hz. is provided. Introduction The analysis of small amplitude vibrations in deformed viscoelastic solids requires knowledge of the equilibrium large strain material properties and the dynamic material properties. The experiments used to determine these material properties may be different than those commonly performed in elastomer laboratories. Most of the experimental techniques described herein to meet these needs are presented in the referenced literature but may not be implemented in commercially available test instruments In practice, all aspects of the material properties of engineering elastomers cannot be represented by one analytical model. Some judgement is required to determine which material properties are the most significant. In the analysis of dynamic properties, it is important to understand the overall material sensitivity to mean strain level, dynamic amplitude and vibration frequency so that a subset of these properties may be judiciously selected and used in analysis. In general the experimental approach is as follows: A. Establish large strain non-linear equilibrium material properties in the range of interest. B. Determine the dynamic properties of superimposed linear vibrations in the frequency, the mean strain and the dynamic amplitude ranges of interest. Measuring the Dynamic Properties of Elastomers for Analysis Figure 8, Small Amplitude Vibration on Large Mean Strain Strain Stress Time Mean Strain Dynamic Strain