高温下聚氨酯软泡压缩力学性能的研究

Research on the compression mechanical properties of flexible polyurethane foam at high temperature

根据聚氨酯软泡的组织构成,将材料的粘弹性分为聚氨酯基体的粘弹性与气体和基体间的摩擦两部分,提出了高温下聚氨酯软泡的一种本构模型。然后,对一类聚氨酯软泡进行了不同恒定温度下材料压缩松弛实验。结果表明,随着温度升高,材料的粘弹性特征越来越来明显,成型性也随之呈现并逐渐加强。最后,根据实验数据,对本文提出的本构模型进行了参数拟合,通过实验结果与模型拟合结果的对比,发现本构模型拟合曲线与实验数据吻合程度高,并且模型的预测结果与实验结果具有很好的一致性,验证了所建模型的正确性。为聚氨酯软泡在高温下的使用与加工提供了理论依据。

According to the structure of flexible polyurethane foam(PU),the viscoelasticity of the material is divided into two parts:the viscoelasticity of polyurethane matrix and the friction between gas and matrix,with which a constitutive model for flexible PU foam in high temperature is put forward.Then compression tests and relaxation tests are conducted on a kind of flexible PU foam under different constant temperatures.Experimentalresults show that with the increase of temperature,the viscoelastic characteristics of the material become more and more obvious,the formability also appears and gradually strengthened.Finally,according to the experimental data,the parameters of the constitutive model proposed in this paper are fitted.Through the comparison of the experimental results and the model fitting results,it is found that the fitting curves of the constitutive model and the prediction are all in consistency with the experimental data,which verifies the correctness of the model.It provides a theoretical basis for the application and processing of polyurethane soft foam at high temperature.