浮空器膜材循环拉伸力学性能及弹性常数研究

Study of the Mechanical Properties and Elastic Constants of Aerostat Envelope Fabric under Cyclic Tensile Loading

对全新飞艇蒙皮膜材Uretek3216L进行了单轴循环拉伸试验,采用自主研发的多功能薄膜双轴拉伸试验机进行5种应力比例下的拉伸试验.探讨了单双轴循环试验的应力应变关系及弹性模量随循环次数的变化规律,对双轴耦合弹性模量的理论公式进行了推导,分析了纬经向应力比对耦合弹性模量的影响规律.结果表明,单轴循环的第15次和第1次循环相比,经纬向弹性模量分别增大了20.7%和39.1%,其中第2次循环增大幅度最大,经纬向均占总增量的60%以上.对于双轴试验,随纬经向应力比R的增大,经向耦合弹性模量增大而纬向减小.确定了膜材的单、双轴应力下的弹性模量和3D应力应变响应曲面.

Series tests were carried out for the new airship envelope fabric Uretek3216L.First,uni-axial cyclic tests were conducted.And then,on the basis of the multi-function bi-axial tension tester developed in SSRC,bi-axial tension tests with five stress ratios were carried out with particular test protocol.Detailed experiment results and elastic modulus and Poisson’s ratio were obtained.The stress-strain relationship and elastic modulus of the membrane material under uni-axial tests and bi-axial tests were obtained at different cycle numbers.Moreover,the relation formula between coupled elastic modulus and stress ratios was proposed and bi-axial stress-strain surfaces were presented.The results have shown that,for the uni-axial cyclic tests,from the 1st to the 15th,the elastic moduli increase by 20.7%in warp and 39.1%in weft of the initial elastic modulus respectively;and the 2nd cycle has the biggest increments in both directions,which are about 60%of the total increment in relevant direction.For bi-axial tensile tests,when the stress ratio increases,the warp direction’s coupled elastic moduli increase and the weft direction’s decrease gradually.