Summary: | The creep behavior of a Twaron CT709® fabric/natural rubber composite under a uniaxial constant stress is studied using three viscoelasticity models with different levels of complexity and a newly developed para-rheological model. The three models employed are a one-term generalized Maxwell (GM n=1) model (consisting of one Maxwell element and an additional spring in parallel), a two-term generalized Maxwell (GMn=2) model (including two parallel Maxwell elements and an additional spring in parallel), and a four-parameter Burgers model. The values of the parameters involved in each model are extracted from the experimental data obtained in this study. The creep tests reveal that the axial strain starts to increase exponentially during the primary stage and then continues to equilibrate linearly with time. The results show that the initial creep response of the composite is predicted fairly well by the GMn=2 model, while the secondary creep is more accurately described by the GMn=1 model. An implicit solution, together with a characteristic retardation time spectrum, obtained using the para-rheological model is found to provide more accurate predictions of the composite creep response than the three viscoelasticity models at both the primary and secondary stages. Copyright © 2010 by ASME.
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