EVA粉体高填充电缆材料蠕变性能及其数学模型拟合

Creep and Mathematics Model Fitting of EVA Cable Highly Filled with Powder

通过蠕变拉伸实验,研究了EVA粉体高填充电缆材料在不同的温度、填料配比及应力水平下的短期蠕变行为,并采用Burgers模型对其蠕变行为进行模拟。结果表明:EVA粉体高填充电缆材料的普弹形变Em、延迟弹性形变Ek和黏性流动形变ηk均表现出对温度、应力的时间依赖性;当填充量都为60%时,氢氧化铝与氢氧化镁复配使用时,产生良好的协同效应,可提高材料的形变能力。比较Burgers模型与Findley模型在不同应力下对高填充复合材料蠕变曲线的拟合度,总体上Burgers模型模拟效果优于Findley模型,而Findley模型在长时蠕变行为的预测上,相对较好。研究对于优化无卤阻燃EVA电缆专用料的配方,以及对于继续深入研究EVA粉体高填充电缆材料的短期蠕变行为,具有重要的实际意义。

The short-term tensile creep behaviors of EVA cable highly filled with powder under different temperature,material ratio and stress levels were studied through tensile creep test.Burgers model was applied to simulate the creep behaviors of the composites.The results showed that the instantaneous elastic modulus Em,retardant elastic modulus Ekand ηkviscosity were obvious correlative to the temperature and stress levels.When the weight ratio of metal hydroxide and EVA was 3∶ 2,a synergistic effect between Al(OH)3and Mg(OH)2was confirmed by improving the ability of the composites deformation.In the short term,the predicted results from Burgers model and Findley power law were in good agreement with the experimental results.In addition,Burgers model clearly showed a better prediction than the one using Findley power law,while the Findley power law was of the good predicting ability over large time scale.The present study can be practically significant to the optimizing formula of special halogen-free flame retardant EVA cable compound,as well as the further study on the short-term tensile creep behaviors of EVA cable highly filled with powder.