MECHANICAL BEHAVIOR OF AMORPHOUS POLYMERS IN SHEAR

Abstract

Abstract: Based on the non-equilibrium thermodynamic theory, a new thermo-viscoelastic constitutive model for an incompressible material is proposed. This model can be considered as a kind of generalization of the non-Gaussian network theory in rubber elasticity to include the viscous and the thermal effects. A set of second rank tensorial internal variables was introduced, and in order to adequately describe the evolution of these internal variables, a new expression of the Helmholtz free energy was suggested. The mechanical behavior of the thermo-viscoelastic material under simple shear deformation was studied, and the "viscous dissipation induced" anisotropy due to the change of orientation distribution of molecular chains was examined. Influences of strain rate and thermal softening produced by the viscous dissipation on the shear stress were also discussed. Finally, the model predictions were compared with the experimental results performed by G’Sell et al., thus the validity of the proposed model is verified.

2010 MSC Number:

ZHANG Yun;HUANG Zhu-ping . MECHANICAL BEHAVIOR OF AMORPHOUS POLYMERS IN SHEAR. Applied Mathematics and Mechanics (English Edition), 2004, 25(10): 1089-1099.

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References

[1] Treloar L R G. The Physics of Rubber Elasticity[M].3rd edition. Oxford: Oxford University Press,1975.
[2] Ward I M. Mechanical Properties of Solid Polymers[M]. 2nd edition. New York: Wiley-Interscience,1983.
[3] James H M, Guth E. Theory of the elastic properties of rubber[J]. J Chem Phys, 1 943,11(10):455-481.
[4] Arruda E M, Boyce M C. Evolution of plastic anisotropy in amorphous polymers during finite straining[A]. In: Boehler J-P, Khan A S Eds. Anisotropy and Localization of Plastic Deformation[C]. London: Elsevier Applied Science, 1991,483-488.
[5] Wu P D, Van der Giessen E. On improved 3-D non-Gaussian network models for rubber elasticity[J]. Mech Res Camm, 1992,19(5):427-433.
[6] Wu P D, Van der Giessen E. On improved network models for rubber elasticity and their applications to orientation hardening in glassy polymers[J]. J Mech Phys Solids, 1993,41(3): 427-456.
[7] G' Sell Christian, Boni Serge. Application of the plane simple shear test for determination of the plastic behavior of solid polymers at large strains[J]. Journal of Materials Science, 1983,18(3): 903-918.
[8] HUANG Zhu-ping, CHEN Jian-kang, WANG Wen-biao. An internal-variable theory of thermoviscoelastic constitutive relations at finite strain[J]. Science in China,Series A,2000,43(5):545-551.
[9] Bataille J, Kestin J. Irreversible processes and physical interpretation of rational thermodynamics[J]. J Non-Equilib Thermodyn, 1979,4(4):229-258.
[10] HUANG Zhu-ping. Fundamentals of Continuum Mechanics[M]. Beijing: Higher Education Publishing House, 2003. (in Chinese)
[11] La Mantia F P, Titomanlio G,Acierno D. The viscoelastic behavior of nylon 6/lithium halides mixtures[J]. Rheol Acta, 1980,19: 88-93.
[12] Aklonis J J, MacKnight W J, Shen M. Introduction to Polymer Viscoelasticity[M]. New York: Wiley-Interscience, 1972.
[13] LIU Kuang-hai, Hatakeyama T. Hand Book of Analytical Chemistry. the 8th Fascicule: Heat Analysis[M]. 2nd ed. Beijing: Chemistry Industry Press, 2000. (in Chinese)
[14] HE Man-jun, CHEN Wei-xiao, DONG Xi-xia. The Physics of Polymers[M]. Shanghai: Fudan University Press, 1990. (in Chinese)
[15] Ashby M F, Jones D R H. Engineering Materials: An Introduction to Their Properties and Applications[M]. Oxford: Pergamon Press, 1980.