考虑温度和加载影响的离子型中间膜拉伸力学性能

Tensile Mechanical Behavior of Ionomer Interlayer Considering Effects of Temperature and Loading Style

摘要:

为研究温度和加载影响的离子型中间膜的拉伸力学性能，在低应变率范围内对其进行了-40 °C ~ 80 °C的单调拉伸试验以及室温下的循环加卸载拉伸试验。基于试验结果，确定了离子型中间膜的力学性能特征指标。结果表明，随着应变率的升高和温度的降低，其强度普遍提高，但极限应变有所降低；断后试件有约80%的不可恢复变形；循环加卸载拉伸曲线的包络线与其相同条件下的单调拉伸试验曲线基本一致，随卸载应变的升高，其加卸载耗能能力提高，而割线卸载模量先减小后增大。基于试验结果，给出了低应变率下的G’Sell本构关系。在此基础上，根据割线卸载模量的变化，提出了加卸载应力-应变的变模量模型，对比模型预测关系曲线与试验曲线，两者吻合较好。

Abstract:

In order to evaluate the tensile mechanical behaviour of ionomer interlayer considering temperature effect and loading effect， monotonic tests at -40 °C ~ 80 °C， as well as cyclic loading-unloading tests at room temperature were conducted on ionomer interlayer specimens at low strain rates. Characteristic mechanical properties are extracted from the test results. As the strain rate increases and the temperature decreases， the material's strength increases but its ultimate strain decreases. The fractured specimen exhibits around 80% plastic deformation. The envelope of the cyclic loading and unloading curve is consistent with that of the monotonic curve. As the unloading strain increases， the hysteretic energy dissipation of the ionomer interlayer increases， while the secant unloading modulus decreases firstly and then increases. Based on the G'Sell model， a constitutive equation for low strain rates is proposed. Furthermore， a variable modulus model is proposed for the prediction of the material's loading-unloading behaviour and verified against the experimental results.