摘要
针对有限元计算对几何参数的需要 ,详细研究了由四步 1∶1法编织的复合材料三维四向矩形截面类型预成形件的表面结构 ,为其建立了较准确的几何模型。以矢量分析方法导出表面纱段轴线、表面纱段与内部纱段的接触线等数学表达式。据此得到该材料表面结构的几何参数值和下面结果 :表面纱段轴线由两条相互对称且位于正交平面上的椭圆弧光滑连接而成 ;同一条纱线的表面段和内部段为光滑连接 ;接触线是椭圆弧。
To meet the need for geometric parameters in finite element investigation,the surface structure of three dimensional(3D) four directional rectangular composite preforms,braided by 4 steps and 1∶1 procedure,is studied, and a more accurate geometry model of the structure is developed. The vector analysis method is used to deduce some mathematic expressions such as axis of yarn(fiber bundle) at fabric surface,contact curve at which surface yarn touches with internal yarn, and etc. These formulas can give geometric parameters of the surface structure of this material, and lead to following results.The axis of yarn at fabric surface is constituted by smooth connection of two symmetric ellipse arcs situating respectively in orthogonal plans,one part of a yarn at fabric surface links another part at interior smoothly and the contact curve is a ellipse arc. A noticeable problem of calculating yarn's interior braiding angle from yarn's surface inclination is also presented in this paper.
出处
《宇航材料工艺》
CAS
CSCD
北大核心
2000年第3期14-19,41,共7页
Aerospace Materials & Technology
