Kapton薄膜单轴拉伸中心撕裂性能研究

Experimental Research on Uniaxial Tensile Center Tearing Behaviors of Kapton Foils

为了探究Kapton薄膜材料中心撕裂对其力学性能的影响,选取7种中心切缝角度(0°,15°,30°,45°,60°,75°,90°)和10种温度工况(−70,−40,−10,0,20,50,80,110,140,170℃)对Kapton薄膜材料沿机器展开方向(machine direction,MD)和与其垂直的方向(transverse direction,TD)进行单轴中心撕裂试验,获取了不同切缝角度和不同温度下的应力-应变曲线,并对其破坏机制进行了探讨。通过对试验现象和数据进行分析,结果表明:Kapton薄膜材料破坏是由裂缝的发展造成,破坏断面呈现出横向的“I”形和“Z”形,切缝缺陷和温度分别对Kapton薄膜材料的抗拉强度和断裂延伸率有着显著的影响;Griffith强度理论对Kapton薄膜材料的中心撕裂强度具有较好的预测。研究所得结论可为Kapton薄膜材料力学性能的研究积累基础数据,同时为充气天线结构的工程应用提供有益参考。

In order to investigate the effect of center tearing on mechanical properties of Kapton foils,seven different types of kerf angles(0°,15°,30°,45°,60°,75°,90°)and ten kinds of temperature conditions(−70,−40,−10,0,20,50,80,110,140,170℃)are selected to carry out uniaxial center tearing tests along machine direction(MD for short)and transverse direction(TD for short)for such foils.The stress-strain curves of the foils are obtained under different kinds of kerf angles and temperature conditions and the failure mechanism is also discussed.By analyzing experimental phenomenon and data,it can be inferred that the foil damage is caused by cracks development and the failure section shows the transverse“I”or“Z”shapes.Both initial kerf defects and tempera⁃tures have great adverse effects on tensile strength and the elongation at the break of the foils.Griffith strength theory can predict the center tearing strength of Kapton foil well.The results obtained can accumulate basic data for mechanical properties of Kapton foil and provide valuable references for application of inflatable antenna structure in future.