For a class of materials called regain-rheologically simple, creep curves at various regain states can be shifted along the time axis in such a manner as to generate a single (master) curve. A constitutive model which exploits the unique time and regain-coupled creep response of these materials is presented. The model is then used to predict the creep response as a function of regain using experimental data obtained from a few simple tests on cellulosic handsheets.
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