浮空器蒙皮膜复合材料单轴拉伸力学性能及弹性常数

摘要

对新型飞艇蒙皮材料在0°、15°、30°、45°、60°、75°、90°七个偏轴方向单轴拉伸循环试验结果进行了分析，给出了残余应变和弹性模量随循环次数的变化规律；得出了由单层板理论推导出的关于弹性模量的本构关系对各功能膜层压合成的平纹织物膜复合材料适用性较差。使用 VIC-2 D数字散斑测量系统测出膜材在拉伸过程中的位移场和应变场，通过位移场求膜材的泊松比和通过应变场验证分析膜材拉伸破坏机制，并可以预测断口形态和位置。采用两种不同规格的试样测试膜材的单轴拉伸强度，通过对比发现采用试样3更能反应材料 Uretek5876实际强度。本文工作对该材料应用于飞艇结构设计和分析具有参考价值。%The experiment results of uniaxial tension of airship envelope material Uretek5876 were analyzed in seven in-plane directions including 0°,15°,30°,45°,60°,75°,90°,which provided the law of residual strain and elasticity modulus with cycle inder.The modulus obtained from the theory of single layer board does not adapt to multi-layer pressure membrane material.VIC-2D digital speckle technique was used in tensile process to obtain the displacement field and strain field.Based on displacement field,the Poisson’s ratio of Uretek 5876 was obtained. Strain field was not only used to analysis tensile failure mechanism,but also can forecast the position and type of fracture.The uniaxial tensile strength was tested by two kinds of specification of the sample,and the sample 3 was found to be more proper to response the actual strength of Uretek 5876.The work in this paper provides reference value for the design and analysis of the airship structure.