飞艇用层压织物类膜材中心撕裂破坏机理模型  

Analytical Model on Mechanical Responses of Laminated Fabrics for Airships under Central Crack Tearing

作　　者：陈建稳[1] 陈务军[2] 周涵[1] 高成军[2] 何世赞 

机构地区：[1]南京理工大学理学院,江苏南京210094 [2]上海交通大学空间结构研究中心,上海200030

出　　处：《东华大学学报（自然科学版）》2016年第3期323-331,共9页Journal of Donghua University(Natural Science)

基　　金：国家自然科学基金资助项目(51278299);江苏省基础研究计划(自然科学基金)资助项目(BK20150775)

摘　　要：中心撕裂破坏是飞艇用层压织物类膜材失效破坏的基本形式之一.基于层压织物类膜材的平纹织物结构特征,建立了具有平面纱线结构的中心切缝撕裂机理模型,该模型应用了“等效纱线”及“应力集中渐变区”两个概念,分别实现模型参数的简化和应力集中区域应力场分布的细化.运用所提机理模型实现了对不同切缝长度时（10~40mm）经纬向层压织物类膜材撕裂破坏行为特征的预测,分析了蒙皮材料撕裂扩展机理,并结合试验结果证实了模型预测的精确性和可行性.由模型分析获得了蒙皮材料在渐变区推移过程中的撕裂承载力及变形特征,发现纱线的失效应变、弹性模量以及编织密度等是影响蒙皮材料撕裂抗力的主要因素.所得结论及研究方法可为层压织物类膜材的强度设计、裂纹止裂分析及结构的安全性评估提供理论参考.Central crack tearing damage is one of the main failure types for laminated fabrics during their serving life. In order to analyze the tear behaviors of laminated fabrics, a new analytical model was developed according to the plain weave structure of the studied materials. Two new concepts--equivalent yarns and narrow transitional zone of stress concentration, were introduced to simplify the parameter model and refine the distribution of stress field in the narrow transitional zone, respectively. The model, with different crack lengths in the range of 10 mm to 40 ram, was validated from the good agreement between the calculated results and the experimental results. Based on the analytical model, the tearing deformation at different narrow transitional zones had been calculated to derive the tearing resisting forces, the tearing propagation mechanism of the envelope materials was analyzed, and it was found that the failure strain and the elastic modulus of the yarn as well as the weaving density of the fabric were the key factors affecting the tearing resisting forces of the envelope materials. Investigations on the tearing mechanism of laminated fabrics will provide significant guidance for the fabric design, crack arrest, and safety assessment of airship structures.

关 键 词：层压织物 中心切缝撕裂 撕裂机理 应力集中渐变区 等效纱线 

分 类 号：V274[航空宇航科学与技术—飞行器设计]