The aim of this work is to investigate the finite deformation behavior of polymeric materials under monotonic loading—unloading. The strain rate sensitivity behaviors of polymeric materials were modeled using viscoplasticity theory based on an overstress (VBO) model. The modeling capability of the VBO model was improved to describe the nonlinear stress—strain behavior of the fully inelastic flow region in loading at small strain level. In this model, the tangent modulus (Et) is taken nonlinearly to simulate this polymeric material behavior. The numerical results were compared to the experimental data in the literature. These results were in good agreement with the experimental data.
Drozdov, A.D. and Christiansen, J.C. (2007). Cyclic Viscoplasticity of Solid Polymers: The Effects of Strain Rate and Amplitude of Deformation , Polymer, 48: 3003-3012.
2.
Dusunceli, N. and Colak, O.U. (2006). High Density Polyethylene (HDPE): Experiments and Modeling, Mech. Time Depend. Mat. , 10: 331-345.
3.
Colak, O.U. ( 2005). Modeling Deformation Behavior of Polymers with Viscoplasticity Theory Based on Overstress, Int. J. Plasticity, 21: 145-160.
4.
Popelar, C.F. , Popelar, C.H. and Kenner, V.H. (1990). Viscoelastic Material Characterization and Modeling for Polyethylene, Polym. Eng. Sci., 30: 577-586.
5.
Lai, J. and Bakker, A. ( 1995). An Integral Constitutive Equation for Nonlinear Plasto-Viscoelastic Behavior of High-density Polyethylene, Polym. Eng. Sci., 35: 1339-1347.
Ariyama, T. and Kaneko, K. ( 1995). A Constitutive Theory for Polypropylene in Cyclic Deformation, Polym. Eng. Sci., 35: 1461-1467.
8.
Zhang, C. and Moore, I.D. ( 1997). Nonlinear Mechanical Response of High Density Polyethylene, Part II: Uniaxial Constitutive Modeling. Polym. Eng. Sci. , 37: 414-420.
9.
Nikolov, S. and Doghri, I. ( 2000). A Micro/Macro Constitutive Model for the Small-deformation Behavior of Polyethylene, Polymer, 41: 1883-1891.
10.
Nikolov, S., Doghri, I., Pierard O., Zealouk, L. and Goldberg, A. ( 2002). Multi-scale Constitutive Modeling of the Small Deformations of Semicrystalline Polymers, J. Mech. Phys. Solids, 50: 2275-2302.
11.
Hasan, O.A. and Boyce, M.C. ( 1995). A Constitutive Model for the Nonlinear Viscoelastic Viscoplastic Behavior of Glassy Polymers, Polym. Eng. Sci., 35: 331-334.
12.
Boyce, M.C., Socrate, S. and Llana, P.G. ( 2000). Constitutive Model for the Finite Deformation Stress-Strain Behavior of Poly(ethylene terephthalate) above the Glass Transition, Polymer, 41: 2183-2201.
13.
Ahzi, S., Makradi, A., Gregory, R.V. and Edie, D.D. ( 2003). Modeling of Deformation Behavior and Strain-induced Crystallization in Poly(ethylene terephthalate) above the Glass Transition Temperature, Mech . Mater., 35: 1139-1148.
14.
Makradi, A., Ahzi, S., Gregory, R.V. and Edie, D.D. ( 2005). A Two-phase Self-consistent Model for the Deformation and Phase Transformation Behavior of Polymers above the Glass Transition Temperature: Application to PET, Int. J. Plasticity, 21: 741-758.
15.
van Dommelen, J.A.W., Parks, D.M., Boyce, M.C., Brekelmans, W.A.M. and Baaijens , F.P.T. (2003). Micromechanical Modeling of the Elasto-Viscoplastic Behavior of Semi-crystalline Polymers, J. Mech. Phys. Solids, 51: 519-541.
16.
Bergstrom, J.S., Kurtz, S.M., Rimnac, C.M. and Edidin, A.A. (2002). Constitutive Modeling of Ultra-high Molecular Weight Polyethylene under Large-deformation and Cyclic Loading Conditions, Biomaterials, 23: 2329-2343.
17.
Ayoub, G., Zaïri, F., Naït-Abdelaziz, M. and Gloaguen, J.M. ( 2009). Modelling Large Deformation Behaviour under Loading-unloading of Semicrystalline Polymers: Application to a High Density Polyethylene, Int. J. Plasticity, 26: 329-347.
18.
Kitagawa, M. and Takagi, H. (1990). Nonlinear Constitutive Equation for Polyethylene under Combined Tension and Torsion, J. Polym. Sci. Pol. Phys, 28: 1943-1953.
19.
Krempl, E. and Ho, K. ( 2000). An Overstress Model for Solid Polymer Deformation Behavior Applied to Nylon66, ASTM STP, 1357: 118-137.
20.
Ho, K. and Krempl, E. ( 2002). Extension of the Viscoplasticity Theory based on Overstress (VBO) to Capture Non-standard Rate Dependence in Solids, Int. J. Plasticity, 18: 851-871.
21.
Colak, O.U. and Dusunceli, N. (2006). Modeling Viscoelastic and Viscoplastic Behavior of High Density Polyethylene (HDPE), J. Eng. Mater-T ASME, 128: 572-578.
22.
Dusunceli, N. and Colak, O.U. (2008). Modelling Effects of Degree of Crystallinity on Mechanical Behavior of Semicrystalline Polymers , Int. J. Plasticity, 24: 1224-1242.
Krempl, E. ( 1996). A Small Strain Viscoplasticty Theory based on Overstress , In: Krausz, A.S. and Krausz, K. (eds), Unified Constitutive Laws of Plastic Deformation, San Diego, Academic Press, pp. 281-318.
25.
Dusunceli, N. , Colak, O.U. and Filiz, C. (2009). Determination of Material Parameters of a Viscoplastic Model by Genetic Algorithm, Mater. Design, 31: 1250-1255.
