THE RESPONSE OF LINEAR VISCOELASTIC MATERIALS IN THE FREQUENCY DOMAIN

Pavement design and performance is discussed in the light of material response, and the need for mapping the rheological properties of pavement materials is emphasized. A method is advanced for defining the response of linear viscoelastic materials by means of algebraic coefficients relating stress to strain which are complex functions of frequency, and equations are developed which express viscoelastic stress-strain laws in the frequency domain, as well as in the time domain. These coefficients are shown to be fundamental material constants which are independent of testing procedures or boundary conditions. Applications to pavement design and performance studies are outlined.