平流层飞艇蒙皮材料撕裂性能影响因素研究

Study on factors influencing tearing properties of stratospheric airship envelope materials

以两种平流层飞艇蒙皮材料为对象,研究了切缝长度、覆盖层和编织密度对其撕裂性能的影响.首先,通过单轴拉伸试验确定了两种蒙皮材料的抗拉强度.然后,通过单侧边切缝试验得到了含不同切缝长度试件的临界撕裂应力.结果表明,蒙皮的临界撕裂应力随着切缝长度的增加而降低,切缝尖端的应力集中进一步降低了其撕裂强度.最后,通过对有、无覆盖层和两种不同编织密度试件的撕裂试验结果对比发现,编织密度小的蒙皮材料具有更高的撕裂强度;同时,覆盖层增加了切缝尖端的应力集中程度,使得蒙皮更易发生撕裂破坏.

Stratospheric airship is a controllable aircraft that can work in the stratosphere for a long time,which has important application prospects in both civil and military fields.As a kind of fabric material,airship envelope material is easy to tear due to minor defects or stress concentration.Therefore,it is very important to study the tearing property of envelope material for airship safety.In this paper,two kinds of stratospheric airship envelope materials were studied to consider the effects of slit length,covering layer and weaving density on tearing property.Firstly,tensile strength of two envelope materials were measured by uniaxial tensile test.Then,the critical tearing stress of specimens with different length of slits were obtained by single edge notched(SEN)tearing test.The results show that the critical tearing stress of envelope material decreases with the increase of slit length,while the stress concentration at the cutting tip further reduces the tearing strength.Finally,through comparing the tearing test results of the specimens with or without coating and specimens with two different weaving densities,it is found that the envelope material with low weaving densities has higher tearing strength.In addition,the coating makes the stress concentration at the tip of the slit more intensive,which causes the envelope material more vulnerable to tearing damage.