老化与折皱损伤对飞艇囊体材料单轴拉伸力学性能影响

采用户外暴露试验模拟飞艇囊体材料的自然老化,利用耐揉搓性试验模拟飞艇气囊在加工、运输、储存、收放和服役过程产生的折皱损伤,研究了飞艇囊体材料Uretek3216-LV在短期老化和折皱损伤作用下的单轴拉伸性能退化规律。通过试验数据分析,得到了短期老化和揉搓次数对单轴拉伸强度以及拉伸弹性模量影响的曲线。结果表明:随着老化时间的增加,材料经、纬向的单轴拉伸强度有所降低,但拉伸弹性模量略有增加;随着揉搓次数的增加,材料的单轴拉伸强度和弹性模量均明显降低;当老化和揉搓共同作用于材料时,随着揉搓次数的增加,老化时间对材料单轴拉伸力学性能的影响逐渐减弱。研究结果可为Uretek3216-LV材料应用于飞艇气囊的结构设计与分析提供重要依据。

Effects of Aging and Creasing on Uniaxial Tensile Properties of Airship Envelope Materials

Outdoor exposure test was used to simulate the natural aging of airship envelope materials.Flexing durability test was used to simulate various creasing damage levels of the material induced in the manufacturing,transportation,storage,launch and service.The degradation of uniaxial tensile properties of an airship envelope material,Uretek3216-LV,under the condition of short-time aging and creasing damages were studied.The influence of short-time aging and flexing cycles on uniaxial tensile strength and elastic modulus of tension was studied by carrying out the analysis of experimental data.It demonstrates that with the increase of aging duration,the material's uniaxial tensile strengths in both warp and weft directions decrease,but their elastic moduli slightly increase.With the increase of flexing cycles,the material's uniaxial tensile strengths and elastic moduli both decrease significantly.For the material experienced both outdoor exposure and flex durability tests,the effects of aging duration on the material's mechanical behaviour gradually become less significant with the increase of flexing cycles.The conclusions provide important evidences on the application of Uretek3216-LV material to the design and analysis of airship envelope structures.