【摘要】 为了研究时间-温度-应力等效原理在PET材料蠕变拉伸中的应用，预测PET材料的长期性能。对PET材料进行恒温度不同应力和恒应力不同温度下的短期拉伸蠕变试验，分析其蠕变行为。结果表明，在测试温度和测试应力范围内，PET材料表现出明显蠕变现象，且蠕变性能具有明显的温度相关性和应力水平相关性。不同温度和不同应力水平下的短期蠕变柔量曲线沿对数时间坐标轴可构建出宽广时域下温度应力耦合的蠕变柔量主曲线，所得温度应力耦合蠕变柔量主曲线基本一致，表明在试验温度和试验应力下，时间-温度-应力等效原理对PET材料有良好的适用性，可以用于PET材料的长期蠕变性能加速表征。此外，比较先温度后应力、先应力后温度和温度应力同时移位三种不同移位顺序下所获得的温度-移位联合移位因子，结果表明三种移位顺序下的联合移位因子近似相等，验证了联合移位因子分步获取的可行性。更多还原

【Abstract】 In order to study the application of time-temperature-stress equivalence principle in creep tensile of PET materials and predict the long-term performance of PET materials, the short-term tensile creep tests of PET materials under different stresses at constant temperature and different temperatures at constant stress were carried out, and the creep behavior was analyzed. The results show that the PET materials exhibit obvious creep phenomenon in the range of test temperature and test stress, and the creep performance has obvious temperature correlation and stress level correlation. The short-term creep compliance curves at different temperatures and different stress levels can construct a creep compliance master curve of temperature-stress coupling in a wide time domain along the logarithmic time coordinate axis. The obtained creep compliance master curves of temperature-stress coupling are basically the same, indicating that under the test temperature and test stress, the timetemperature-stress equivalence principle has good applicability to PET materials and can be used to accelerate the characterization of long-term creep properties of PET materials. In addition, the temperature-displacement combined shift factors obtained under three different shift orders of temperature first and stress later, stress first and temperature later, and temperature and stress shift simultaneously were compared. The results show that the combined shift factors under the three shift orders are approximately equal, which verifies the feasibility of step-by-step acquisition of the combined shift factor.更多还原