A New Approach to Temperature Shift Functions in Modeling Complex Modulus Damping Data

Abstract

A new approach to determining the temperature shift function and its utility in smoothing, interpolating, and modeling a set of complex modulus data are described in detail and examples are given. A set of experimental data to characterize the dynamic mechanical properties of a viscoelastic damping polymer typically includes the real component of complex modulus and the material loss factor as well as the experimental frequency and temperature. The set of data must be made useful for design purposes. The present approach analytically represents the wicket plot loss factor as a function of the modulus magnitude. A ratio of polynomials is then used to model the complex modulus as a function of reduced radian frequency. The perpendicular distance from each experimental point to the wicket plot is used to calculate the temperature shift function.