Indentation tests viscoelastic behavior

The durometer test is based on the penetration of a specific type of indentor when forced into the material under specified conditions. The indentation hardness is inversely related to the penetration and is dependent on the elastic modulus and viscoelastic behavior of the material. The geometry of the indentor and the applied force influence the measurements such that no simple relationship exists between the measurements obtained with one type of durometer and those obtained with another type of durometer or ottrer instruments used for measuring hardness (10). 

FIGURE 33.13 Outline of the approach to explore viscoelastic indentation test results. A standard linear model approximation of indentation testing of a viscoelastic material is used in conjunction with the heredity integral and relationships between indent depth and strain, and indent load and stress, to arrive at an approximation of the indentation behavior. 

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