A Viscoelastic Constitutive Model for the Creep Response of Polyurethane Rubber

Published

August 1, 1998

Author(s)

V Rouiller, G B. McKenna

Abstract

A viscoelastic model is developed to describe the behavior of a polyurethane rubber provided to NIST by NSWC, Carderock. The model is based on concepts of time-dependent rubber elasticity and single integral models of viscoelasticity. The strain energy density function is assumed to be of a Valanis-Landel form, while its time-dependence is analyzed using the perfect elastic fluid model of Bernstein, Kearsley and Zapas. In addition, time-strain separability and time-temperature superposition are assumed to apply to the polyurethane in the temperature range of interest. Single step stress relaxation experiments in uniaxial extension are used to determine the model parameters. From these, multiple step stress relaxation and creep histories are applied to the material and it is found that the model can describe the nonlinear time-dependent viscoelastic response of the polyurethane resin to these cyclic histories to within approximately 10% of the maximum load or deformation value applied.

Citation

NIST Interagency/Internal Report (NISTIR) - 6177

Report Number

6177

NIST Pub Series

NIST Interagency/Internal Report (NISTIR)

Pub Type

NIST Pubs

Keywords

creep, PEN, relaxation process, time-aging time superposition, viscoelasticity

Citation

Rouiller, V. and McKenna, G. (1998), A Viscoelastic Constitutive Model for the Creep Response of Polyurethane Rubber, NIST Interagency/Internal Report (NISTIR), National Institute of Standards and Technology, Gaithersburg, MD (Accessed December 26, 2024)