Time-Temperature-Stress Equivalence Applied to Accelerated Characterization of Creep Behavior of Viscoelastic Polymer


Article Preview

Temperature induced change, and stress induced change as well, in intrinsic timescale were investigated by nonlinear creep tests on poly(methyl methacrylate). With four different experimental temperatures, from 14 to 26 degrees centigrade, time-dependent axial elongations of the specimen were measured at seven different stress levels, from 14 MPa to 30 MPa, and modeled according to the concept of time-temperature-stress equivalence. The test duration was only 4000 seconds. The corresponding temperature shift factors, stress shift factors and temperature-stress shift factors were obtained according to the time-temperature superposition principle (TTSP), the time-stress superposition principle (TSSP) and the time-temperature-stress superposition principle (TTSSP). The master creep compliance curve up to about two-year at a reference temperature 14 degrees centigrade and a reference stress 14 MPa was constructed by shifting the creep curves horizontally along the logarithmic time axis using shift factors. It is shown that TTSSP provides an effective accelerated test technique in the laboratory, the results obtained from a short-term creep test of PMMA specimen at high temperature and stress level can be used to construct the master creep compliance curve for prediction of the long-term mechanical properties at relatively lower temperature and stress level.



Key Engineering Materials (Volumes 353-358)

Edited by:

Yu Zhou, Shan-Tung Tu and Xishan Xie




R. G. Zhao et al., "Time-Temperature-Stress Equivalence Applied to Accelerated Characterization of Creep Behavior of Viscoelastic Polymer", Key Engineering Materials, Vols. 353-358, pp. 1386-1389, 2007

Online since:

September 2007




[1] M.L. Williams, R.F. Landel and J.D. Ferry: J. Amer. Chem. Soc. Vol. 77 (1955), p.3701.

[2] S.C. Sharda and N.W. Tschoegl: Journal of Rheology Vol. 20 (1976), p.361.

[3] R.A. Schapery: Polymer Engineering and Science Vol. 9 (1969), p.295.

[4] S.C. Yen and F.L. Williamson: Composites Science and Technology Vol. 38 (1990), p.103.

[5] W. Brostow: Materials Research Innovations Vol. 3 (2000), p.347.

[6] W.B. Luo, T.Q. Yang and Q.L. An: Acta Mechanica Solida Sinica Vol. 14 (2001), p.195.

[7] S. Jazouli, W.B. Luo, F. Bremand and T. Vu-Khanh: Polymer Testing Vol. 24 (2005), p.463.

[8] R.G. Zhao, W.B. Luo, C.H. Wang and X. Tang: Key Eng. Mater. Vol. 324-325 (2006), p.731.

[9] J.J. Aklonis, W.J. MacKnight: Introduction to Polymer Viscoelasticity, 2nd edition (John Wiley and Sons, New York 1983) 1 2 3 4 5 6 7 8 -3. 56 -3. 52 -3. 48 -3. 44 -3. 40 -3. 36 -3. 32 -3. 28 -3. 24 -3. 20 log(J(t) / MPa-1 ) log(t / s) Fig. 3. Master creep compliance curve at 14 MPa and 14 o C.