Stratospheric airships are promising aircraft, usually designed as a non-rigid airship. As an essential part of the non-rigid airship, the envelope plays a significant role in maintaining its shape and bearing the external force load. Generally, the envelope material of a flexible airship consists of plain-weave fabric, composed of warp and weft fibre yarn. At present, biaxial tensile experiments are the primary method used to study the stress–strain characteristics of such flexible airship materials. In this work, biaxial tensile testing of UN-5100 material was carried out. The strain on the material under unusual stress and the stress ratio were obtained using Digital Image Correlation (DIC) technology. Also, the stress–strain curve was corrected by polynomial fitting. The slope of the stress–strain curve at different points, the Membrane Structures Association of Japan (MSAJ) standard and the Radial Basis Function (RBF) model were compared to identify the stress–strain characteristics of the materials. Some conclusions on the mechanical properties of the flexible airship material can be drawn and will play a significant role in the design of such envelopes.

中文翻译：

---

UN-5100平流层飞艇外壳材料的力学性能

平流层飞艇是很有前途的飞机，通常设计为非刚性飞艇。作为非刚性飞艇的重要组成部分，外壳在保持其形状和承受外力载荷方面起着重要作用。通常，柔性飞艇的外壳材料由平纹织物组成，由经纱和纬纱纤维纱组成。目前，双轴拉伸实验是研究这种柔性飞艇材料应力-应变特性的主要方法。在这项工作中，对 UN-5100 材料进行了双轴拉伸试验。使用数字图像相关（DIC）技术获得材料在异常应力下的应变和应力比。此外，通过多项式拟合校正应力-应变曲线。应力-应变曲线在不同点的斜率，日本膜结构协会 (MSAJ) 标准和径向基函数 (RBF) 模型进行了比较，以确定材料的应力-应变特性。可以得出一些关于柔性飞艇材料力学性能的结论，并将在此类外壳的设计中发挥重要作用。