A viscoelastic–plastic constitutive model for uniaxial ratcheting behaviors of polycarbonate

Abstract

In this paper, a modified viscoelastic–plastic constitutive model has been proposed on the framework of Anand's work to describe the uniaxial ratcheting behavior of polycarbonate (PC) under tension–tension cyclic loading. The experimental observation illustrates that the previously accumulated deformation has an assignable influence on the subsequent material response during the ratcheting process of PC. Thus, the deformation resistance in the viscoelastic micromechanism is assumed to be evolving with the local accumulated inelastic strain rather than keeping unchanged in the original Anand's model. The proposed model is validated firstly by the monotonic tension and creep experiment results of PC. Then, its capability to describe the uniaxial ratcheting behaviors is compared with Anand model. Finally, the modified model is adopted to study the effect of mean stress, stress amplitude, loading rate, and peak holding time on the ratcheting behaviors of PC. It is shown that the proposed model can predict reasonably the uniaxial tension–tension ratcheting behavior of polymer. POLYM. ENG. SCI., 55:2559–2565, 2015. © 2015 Society of Plastics Engineers

A compact constitutive model to describe the viscoelastic-plastic behaviour of glassy polymers: Comparison with monotonic and cyclic experiments and state-of-the-art models

“…In detail, the proposed approach relies on the pioneering model of Haward and Thackray (1968) for glassy polymers (based on Eyring's theory) that is augmented by a single set of internal variables able to predict the missing viscous deformation behavior (area/shape of the hysteresis loops) and the nonlinear cyclic hardening (ratcheting behavior) in three dimensions. Against the state-of-the-art models of Anand and Gurtin (2003); Anand and Ames (2006); Jiang et al (2015) that can also predict the cyclic deformation behavior well, the elastic portion of the deformation is described by a single element a) clearly separated from viscoelasticplastic elements in accordance with the classical Haward and Thackray (1968) -model. As a result, the nonlinear Langevin spring c) applied in the model to describe the anisotropic hardening of amorphous network structures is modeled solely using the viscous deformation (as originally proposed in Boyce et al (1989) for three dimension).…”

“…A recent research that is focused on the ratcheting and fatigue behaviors under cyclic loading processes (group 4) can be found from Krairi and Doghri (2014); Jiang et al (2015); Beesley et al (2017); Kang and Kan (2017); Shojaei and Volgers (2018); Holopainen and Barriere (2018); Qi et al (2019), i.e. work on the cyclic deformation behavior of amorphous polymers is very limited.…”

“…A hyperelastic-viscoplastic model in Shojaei and Volgers (2018) and a parallel rheological network model (elastic-viscoplastic) in Qi et al (2019) provide capable tools for the investigation of both low and high cycle regimes of a highly-crystalline and semicrystalline polymers, respectively. Considering glassy polymers, however, both the viscoelastic and plastic elements are needed to accurately predict long-term creep/recovery and thereby the cyclic deformation behavior (ratcheting and shape/area of the loops), Anand and Ames (2006); Krairi and Doghri (2014); Jiang et al (2015).…”

Viscoplastic parameter identification of temperature‐dependent mechanical behavior of modified polyphenylene oxide polymers

“…In addition, the MPPO plastic properties for the tensile simulation are presented in Fig. . …”

Experimental and numerical investigations of evaluation criteria and material parameters' coupling effect on polypropylene scratch

“…As reported by Jiang et al , the simplified constitutive model shows a similar tendency for the scratch behavior of PP with the true stress–strain curve model. The complex material properties, such as viscosity , should be considered to quantitatively describe the scratch deformation in the future work. To cover the ranges of E and σ y of the prepared PP specimens, the values of E used in the FE simulations range from 500 to 1,350 MPa, as well as σ y from 20 to 33 MPa, respectively.…”