Stress-dependence of the intrinsic time of viscoelastic materialsis investigated. The influence of stress level on the intrinsic timeis considered to be similar to that of temperature, pressure, solventcon- centration...Stress-dependence of the intrinsic time of viscoelastic materialsis investigated. The influence of stress level on the intrinsic timeis considered to be similar to that of temperature, pressure, solventcon- centration, damage and physical aging. Thetime-temperature-stress equivalence principle is proposed, byemploying which, the creep curves at different temperatures andstress level can be shifted into a master curve at referencetemperature and stress level.展开更多
Nonlinear viscoelastic creep properties of poly （methyl methacrylate） at various temperatures and stress levels were measured in short-term tests to check the applicability of time-temperature-stress superposition p...Nonlinear viscoelastic creep properties of poly （methyl methacrylate） at various temperatures and stress levels were measured in short-term tests to check the applicability of time-temperature-stress superposition principle, which is the combined form of time-temperature superposition principle and time-stress superposition principle. A unified master creep compli- ance curve was constructed from the short-term tests by joint application of time-temperature superposition and time-stress superposition. The unified master curve establishes the creep com- pliance over two years, which is 4.2 decades longer than the test duration. Moreover, it is verified that in nonlinear viscoelastic cases, the time-temperature shift factors are dependent on stresses at which the shifts are applied, while the time-stress shift factors are dependent on temperatures.展开更多
基金the Nalional Natural Science Foundation of China (No.19632030,50003005)the Education Committee of Hunan Province (No.99C122)
文摘Stress-dependence of the intrinsic time of viscoelastic materialsis investigated. The influence of stress level on the intrinsic timeis considered to be similar to that of temperature, pressure, solventcon- centration, damage and physical aging. Thetime-temperature-stress equivalence principle is proposed, byemploying which, the creep curves at different temperatures andstress level can be shifted into a master curve at referencetemperature and stress level.
基金supported by NSFC(No. 11172256)NCET (No. NCET-08-0685)+1 种基金Key Project of Chinese Ministry of Education (No. 209085)Aid Program for Science and Technology Innovative Research Team in Higher Educational Institutions of Hunan Province
文摘Nonlinear viscoelastic creep properties of poly （methyl methacrylate） at various temperatures and stress levels were measured in short-term tests to check the applicability of time-temperature-stress superposition principle, which is the combined form of time-temperature superposition principle and time-stress superposition principle. A unified master creep compli- ance curve was constructed from the short-term tests by joint application of time-temperature superposition and time-stress superposition. The unified master curve establishes the creep com- pliance over two years, which is 4.2 decades longer than the test duration. Moreover, it is verified that in nonlinear viscoelastic cases, the time-temperature shift factors are dependent on stresses at which the shifts are applied, while the time-stress shift factors are dependent on temperatures.
