双轴经编织物膜材刺破性能数值模型研究

MODEL ANALYSIS FOR STABBING PERFORMANCE OF BIAXIAL WARP-KNITTED FABRIC MEMBRANES

刺入破坏是经编织物类膜材破坏失效的基本形式之一,膜材自身的刺破力学性能对膜结构安全至关重要。本文针对双轴经编织物类膜材PVDF 8028进行双向限制下的刺破仿真,应用ABAQUS软件建立考虑纱线与基体细观结构的刺破数值模型。通过设置方锥与片状刺具两种刺具形态,在细观层面分析经编织物在不同刺具下的刺破形态特征,系统考察入刺水平转角以及入刺角度对膜材刺破性能的影响规律,另外构建类四棱锥刺入理论模型并通过理论校核证实了数值模型的准确性与可行性。研究结果表明:随着方锥刺具入刺水平转角增加,膜材刺破强度呈现下降趋势,当水平转角由0°增加至90°,刺破强度降低达39.39%;随着片状刺具刺入角度的增加,刺破强度呈现先增大后减小的趋势,峰值刺破力随刺破角度增加呈现倒"V"形的变化特征。所得结论可为膜材料的损伤分析及膜结构的安全性评估提供有益参考。

Stabbing damage is one of the main failure types for warp-knitted fabric membranes during their serving life.And the stabbing mechanical properties of fabric membranes are extremely important for the safety of membrane structures.The stabbing performances of biaxial warp-knitted fabric membranes(PVDF 8028)were studied through numerical method.The numerical model of stabbing considering the micro structure of yarns and matrix is established by ABAQUS software.By introducing the square cone punch and sheet punch,the morphological characteristics of PVDF 8028 under different punches were analyzed on mesoscale,and the effects of different stabbing angles were systematically investigated.The FEM models were validated from the good agreement between the FEM results and the theoretical results.The results show that,for the square cone punch,the stabbing strength of the membrane material decreases as the horizontal stabbing angle of the square cone punch increases,and the stabbing strength reduction reaches 39.39%when the horizontal stabbing angle grows from 0°to 90°.In terms of the sheet punch,with the increase of the stabbing angle,the stabbing strength shows a tendency that it increases at first and then decreases,and the peak stabbing force-stabbing angle curve shows an inverted"V"shaped characteristic as the stabbing angle increases.The conclusions obtained could provide useful references for damage assessment and safety analysis of membrane structures.