聚丙烯木塑复合材料蠕变行为的模拟与预测

Modeling and Prediction of Creep Behavior of PP/Wood-Flour Composite

通过三点弯曲蠕变试验,研究了聚丙烯木塑复合材料在23℃左右室内环境五种应力水平下的短期蠕变行为,并采用四元件模型对其蠕变行为进行模拟。依据时间-温度-应力等效原理,以5MPa为参考应力水平,将其它四种应力水平下的蠕变曲线移位成5MPa应力水平下的主曲线,从而可以预测聚丙烯木塑复合材料在5MPa应力水平下大约3年内的蠕变行为。

The short-term flexural creep behaviors of polypropylene/wood-flour composites under different stress levels were studied through three-point flexural creep test at ambient temperature. Four-Element Model was applied to simulate the creep behaviors of the composites. The results show that the creep behaviors of the wood/polypropylene（PP） composites have obviously correlation to the stress levels. The instantaneous elastic modulus E1,retardant elastic modulus E2？and η2？viscosity as well as permanent viscous flow viscosity η3？show a decreasing tendency with the increase of stress level. By application of the time-temperature-stress equivalence principle,a creep compliance master curve up to about 3 years at a reference stress level 5 MPa was constructed by horizontally shift the short-term creep experimental data of wood/PP composite at high stress levels.