织物膜材弹性参数在应力空间上响应特征及非线性本构分析

Response Characteristics of Elastic Parameters of Woven Fabrics in Stress Space and a Nonlinear Constitutive Analysis

为揭示飞艇用层压类膜材弹性参数在平面应力空间上的响应特征,首先以高性能蒙皮材料Uretek3216LV为研究对象开展一系列双轴拉伸试验,获得多比例应力应变关系数据;然后运用MATLAB软件进行数值处理,分析得出应变及弹性参数在应力空间上的响应曲面特征.基于积分加权方法,分析了弹性参数在不同应力水平及应力比例上变化规律.研究发现正交互补性质在蒙皮材料弹性参数计算时的适用性不足,且材料弹性参数表现出明显正交异性特征.另外,层压织物膜材异于均质材料,大泊松比(>0.5)的存在是其经纬纱间复杂相互作用及变形机理的体现.

In order to reveal the response characteristics of the laminated fabric for airships under plane stresses, a series of biaxial tensile tests were first conducted on high-performance envelope materials Ure- tek3216LV. Based on the stress-strain data obtained from the biaxial tensile tests, the response surfaces of strain and elastic parameters were displayed using the MATLAB program. Using an integrated weigh- ting method, the characteristics of elastic parameters affected by the stress levels and stress ratios were an- alyzed. The results indicate that reciprocal relationship doesn＇t apply to the constitutive model of laminated fabrics, and obvious orthotropy of the elastic parameters can be observed for different stress levels and stress ratios. In addition, the large value of Poisson＇s ratio （〉0.5） can be attributed to the complex inter- action and deformation mechanism of warp and weft yarns which make the laminated fabrics different from homogeneous materials which makes the laminated fabric different from homogeneous materials.