平纹机织叠层复合材料飞轮弹性参数预测及测量

针对纤维缠绕复合材料高速飞轮径向分层问题，提出环向和径向同时强化的圆环平纹织物结构，环向纱束为单一纤维束连续织造。建立了“平头梭形”截面的单胞模型，兼顾双向纱束轮廓差异。基于扇形单胞和矩形单胞结构相似性，定义了“等参数”织造约束条件。采用体积平均法预测圆环织物扇形单胞等效弹性参数，并采用轮缘径向多层分割模型，分析了机织飞轮旋转载荷下的应力和变形特征及其影响参数，轮缘理论计算位移与圆标记法径向变形测量结果一致。机织复合材料飞轮测试极限圆周速度为889 m/s，储能密度为63.7 Wh/kg。理论分析和实验表明，环形织构的双强化理论可行，能够获得比缠绕飞轮更高的旋转速度。 

Elastic parameters prediction and measurement of plain woven laminated composite flywheel

Considering radial delamination of fiber winding composite flywheel at high speed, an annular plain woven fabric with both circumferential and radial reinforcement was proposed, and the prominent feature of new texture was that the circular yarn was continuously woven by a single fiber bundle. The representative volume unit cell with "flat spindle" section was established to deal with the differences between bidirectional yarn profiles. By means of structural similarity between sectorial and rectangular unit cell, constraint conditions for isoparametric weaving were defined. The volume averaging method was used to predict effective elastic parameters for sectorial unit cell of ring fabric. Based on the idea of multi-layered segmentation of rims, the stress and deformation characteristics of woven flywheel under rotating load and correlative influencing parameters were analyzed. The theoretical displacement shows good agreement with radial deformation measurement results using circles marking method. The maximum tangential speed of woven flywheel achieves 889 m/s, and the corresponding energy density reaches 63.7 Wh/kg. Both theoretical analysis and experimental results prove that the bidirectional reinforcement theory of circular texture is practicable. And woven composite flywheel is well promising in technological process to achieve higher rotation speed than traditional winding ones.