飞艇囊体膜材弹性常数双向拉伸测试与分析方法

Bi-axial tensile test method and analytical algorithm of elastic constants for the airship envelope fabric

飞艇囊体膜材弹性常数是飞艇结构设计、结构分析的基础.根据正交异性平面应力模型假设,推导了膜材4参数列式,经纬向模量与泊松比.介绍了膜材双向拉伸试验方法、试件设计与加载.以单向反复试验确定膜材经纬向张拉刚度比值,由双向拉伸试验最小二乘法拟合应力应变曲线得耦合弹性模量值,考虑测量数据误差模型,推导出膜材双向拉伸试验解耦弹性常数计算值列式.最后分析得到了系列飞艇囊体膜材弹性常数.本文对飞艇结构设计与研究具有参考价值,试验与分析方法可用于建筑膜材弹性常数测试与计算.

The elastic constants of the airship envelope fabric are the basis of the structural analysis and design of airship. On the assumption of orthogonaI planar stress model, the four-elastic-constant formulas were developed for the E-modulus and Poisson＇s ratio of warp and weft respectively. Bi-axial tensile test, specimen and loading procedure were presented briefly for the bi-axial test of fabric. The E-modulus ratio of warp and weft were assumed according to the cycling load of fabric uni-tension test. The coupled test E- modulus was calculated from the least norm least square best-of-fit stress-strain curves. The un-coupled E- modulus constants were thus formulated with respect to the bi-axial tensile test of fabric. Finally, series of four-elastic-constant were obtained for the airship envelope fabric. The presented works are valuable to the structural design and research, and can be used for elastic constant test and calculation in civil fabric.