Application of time-temperature-stress superposition principle on the accelerated physical aging test of polycarbonate

A new accelerated characterization model for creep performances was briefly introduced first, which considers both the effects of temperature and stress level, named time-temperature- stress superposition principle (TTSSP). TTSSP assumes that the influence of stress level on the intrinsic time is similar to that of temperature for the creep behavior, as well as damage and physical aging. The creep curves at different state can be shifted into a master curve at reference state using TTSSP. Then the long-term creep behavior of viscoelastic materials at lower temperature and/or stress level can be predicted from the short-term ones. Finally, TTSSP was used to investigate the nonlinear creep behavior of high-density polyethylene (HDPE). It was shown that the long-term creep behavior of HDPE can be predicted successfully.

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

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.353-358.1386 ◽

2007 ◽

Vol 353-358 ◽

pp. 1386-1389 ◽

Cited By ~ 1

Author(s):

Rong Guo Zhao ◽

Wen Bo Luo ◽

Chu Hong Wang ◽

Xin Tang

Keyword(s):

Temperature Stress ◽

Stress Level ◽

Creep Compliance ◽

Superposition Principle ◽

Test Duration ◽

Nonlinear Creep ◽

Creep Tests ◽

Test Technique ◽

Compliance Curve ◽

Stress Superposition

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.

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Time-temperature-stress superposition principle of PMMA’s crazing damages under creep condition

Journal of Central South University of Technology ◽

10.1007/s11771-007-0273-z ◽

2007 ◽

Vol 14 (S1) ◽

pp. 318-323 ◽

Cited By ~ 3

Author(s):

Zhi-da Li ◽

Hong-jun Liu ◽

Rong-feng Zhang ◽

Hui Yi

Keyword(s):

Temperature Stress ◽

Superposition Principle ◽

Creep Condition ◽

Stress Superposition

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Application of Time-Temperature-Stress Superposition Principle to Nonlinear Creep of Poly(methyl methacrylate)

Engineering Plasticity and Its Applications - Key Engineering Materials ◽

10.4028/0-87849-433-2.1091 ◽

2007 ◽

pp. 1091-1096

Author(s):

Wen Bo Luo ◽

Chu Hong Wang ◽

Rong Guo Zhao

Keyword(s):

Methyl Methacrylate ◽

Temperature Stress ◽

Superposition Principle ◽

Nonlinear Creep ◽

Poly Methyl Methacrylate ◽

Stress Superposition

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Application of Time-Temperature-Stress Superposition Principle to Nonlinear Creep of Poly(methyl methacrylate)

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.340-341.1091 ◽

2007 ◽

Vol 340-341 ◽

pp. 1091-1096 ◽

Cited By ~ 16

Author(s):

Wen Bo Luo ◽

Chu Hong Wang ◽

Rong Guo Zhao

Keyword(s):

Methyl Methacrylate ◽

Temperature Stress ◽

Superposition Principle ◽

Temperature Shift ◽

Tensile Creep ◽

Uniaxial Tensile ◽

Test Duration ◽

Nonlinear Creep ◽

Poly Methyl Methacrylate ◽

Stress Superposition

The uniaxial tensile creep of a commercial grade Poly(methyl methacrylate) was measured for 4000 seconds under various temperatures and stress levels ranging from 14 oC to 26 oC and 6 MPa to 32 MPa. The resultant creep compliance curves depart from each other for stresses beyond a critical value which varies with temperature, indicating nonlinear viscoelastic behavior. The time-temperature-stress superposition principle (TTSSP) was used to construct a smooth master compliance curve with a much longer time-scale interval from the short-term tests at higher stresses and temperatures. It is shown that the master curve covers a period of over 290 days, which is nearly 3.9 decades longer than the test duration. Moreover, it is verified that the time-temperature shift factors are dependent on stresses at which the shifts are applied, and that the time-stress shift factors are dependent on reference temperatures.

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Mechanical Integrity Degradation and Control of All-Solid-State Lithium Battery with Physical Aging Poly (Vinyl Alcohol)-Based Electrolyte

Polymers ◽

10.3390/polym12091886 ◽

2020 ◽

Vol 12 (9) ◽

pp. 1886

Author(s):

Yaolong He ◽

Shufeng Li ◽

Sihao Zhou ◽

Hongjiu Hu

Keyword(s):

Solid State ◽

Aging Time ◽

Vinyl Alcohol ◽

Physical Aging ◽

Rupture Strength ◽

Superposition Principle ◽

Solid Polymer ◽

Poly Vinyl Alcohol ◽

Characteristic Relaxation Time ◽

Mechanical Integrity

Ensuring the material durability of an electrolyte is a prerequisite for the long-term service of all-solid-state batteries (ASSBs). Herein, to investigate the mechanical integrity of a solid polymer electrolyte (SPE) in an ASSB upon electrochemical operation, we have implemented a sequence of quasi-static uniaxial tension and stress relaxation tests on a lithium perchlorate-doped poly (vinyl alcohol) electrolyte, and then discussed the viscoelastic behavior as well as the strength of SPE film during the physical aging process. On this basis, a continuum electrochemical-mechanical model is established to evaluate the stress evolution and mechanical detriment of aging electrolytes in an ASSB at a discharge state. It is found that the measured elastic modulus, yield stress, and characteristic relaxation time boost with the prolonged aging time. Meanwhile, the shape factor for the classical time-decay equation and the tensile rupture strength are independent of the aging history. Accordingly, the momentary relaxation modulus can be predicted in terms of the time–aging time superposition principle. Furthermore, the peak tensile stress in SPE film for the full discharged ASSB will significantly increase as the aging proceeds due to the stiffening of the electrolyte composite. It may result in the structure failure of the cell system. However, this negative effect can be suppressed by the suggested method, which is given by a 2D map under different lithiation rates and relative thicknesses of the electrolyte. These findings can advance the knowledge of SPE degradation and provide insights into reliable all-solid-state electrochemical device applications.

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