Thank you very much. In this paper, the author has applied a subroutine UMAT for the anisotropic viscoelasticity calculation in Abaqus. But according to you, we can't preform a such calculation directly in Abaqus without subroutine UMAT? Looking forword for your answer. Thank you.
To my knowledge (which is a few years old) there is no anisotropic viscoelastic material model in Abaqus. More than 15 years ago (though) we had to write an UMAT as well.
U can determine the visco-elastic behaviour of anisotropic material in aqueous solution using cone-plate rheometer. This instruments has peltier control so that u can study behaviour at different temperature. Depending on the behaviour of ur material u can feet in different regression model such as newtonian ,non-newtonian, Bhingham and so on available in the software u do not have to go for any calculation you will get calculated values with desired units. For other quantitative calculation you refer book of Polymer science by Bilmeyer