摘要
时间-温度-应力等效原理是时间-温度等效原理的延伸,可用于材料力学行为的加速表征,通过短期实验来预测材料的长期力学性能。针对PMMA试件在不同温度、不同应力水平条件下的蠕变实验,分析PMMA蠕变行为的非线性特性。本文应用时间-温度-应力等效原理,得到相应的温度移位因子、应力移位因子和温度-应力联合移位因子,构建了参考温度和参考应力水平条件下的蠕变柔量主曲线。理论和数值计算表明,较高温度和应力水平下的PMMA短期蠕变实验可用于预测其在较低温度和应力水平下的长期蠕变行为。
In the theoretical framework of free volume, the effect of stress levels on the intrinsic time scales of polymeric materials is considered to be similar to that of temperature, pressure, moisture, solvent concentration, damage, and physical aging. In this paper, such effect was investigated by nonlinear creep tests of poly（methyl methaerylate） （PMMA） under different temperatures. The test duration was 4000 seconds. The corresponding temperature shift factors, stress shift factors and temperature-stress shift factors were obtained according to the time-temperature-stress superposition principle, and the creep compliance master curve up to about 30 days at a reference temperature 22 ℃ and a reference stress 14 MPa was constructed. It is shown that the time-temperature-stress superposition principle 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.
出处
《高分子材料科学与工程》
EI
CAS
CSCD
北大核心
2007年第2期218-221,226,共5页
Polymer Materials Science & Engineering
基金
国家自然科学基金资助项目(10572123)
湖南省自然科学基金项目(05JJ30014)
湖南省教育厅资助项目(05C100)
先进材料及其流变特性教育部重点实验室开放课题
