SOME ASYMPTOTIC RESULTS FOR HIGH-RATES OF STRAIN

The predictions of some constitutive equations for rheological behavio ur at high rates of strain are investigated. One new result is the for mal establishment of limits for shear flow of an integral model which uses the Seth strain measure. The work is related to earlier work on u niaxial and planar extension for rate equation models. Old and new res ults are tabulated and the behaviour of different models is classified . A recent idea of Harlen is used to 'fix up' the upper convected Maxw ell model tin the sense of removing the upper limit on rate of strain for steady extensional flow). (C) 1998 Elsevier Science B.V. All right s reserved.