航空学报 > 2009, Vol. 30 Issue (7): 1236-1242

基于细观刚度模型的缠绕复合材料结构有限元分析方法

李俭,温卫东,崔海涛,徐颖   

  1. 南京航空航天大学 能源与动力学院
  • 收稿日期:2008-05-19 修回日期:2008-08-24 出版日期:2009-07-25 发布日期:2009-07-25
  • 通讯作者: 李俭

Finite Element Method for Structure Analysis of Filamentwound  Composite Based on Micro Stiffness Model

Li Jian, Wen Weidong, Cui Haitao, Xu Ying   

  1. College of Energy and Power Engineering, Nanjing University of Aeronautics and Astronautics
  • Received:2008-05-19 Revised:2008-08-24 Online:2009-07-25 Published:2009-07-25
  • Contact: Li Jian

摘要: 缠绕复合材料结构分析是缠绕复合材料力学性能研究及应用的重要基础。发展了一种缠绕复合材料结构分析有限元方法,该方法基于缠绕复合材料细观刚度模型,通过建立细观刚度场与整体结构的映射关系,将缠绕复合材料细观刚度模型引入缠绕复合材料结构有限元分析中。采用各向异性单元,几何模型与网格划分等过程不需要进行复杂的处理,单元材料属性采用细观刚度模型计算,并通过已建立的细观刚度场和整体结构的映射关系输入。建立了缠绕复合材料结构有限元分析的流程,采用MATLAB程序编写了细观刚度场计算程序,采用ANSYS提供的APDL语言开发了几何建模、分网、读入刚度矩阵等相应分析程序,最后进行了算例分析。算例结果表明,缠绕复合材料内部各层应力应变呈周期性分布,应力应变在纤维交叉和波动区域有所变化,纤维波动对局部应力具有放大作用;纤维走向的交替造成内部剪切应力的正负交替;纤维弯曲引起的局部刚度下降造成局部的应变较大。与传统的经典层合板理论或有限元方法相比,在缠绕复合材料有限元分析中,采用基于傅里叶级数的细观刚度模型,可以反映材料内部细观结构对应力应变分布的影响;同时,方法简单,便于程序实现。

关键词: 缠绕, 复合材料, 有限元方法, 细观刚度, 结构分析

Abstract: Finite element analysis (FEA) of filamentwound composites is the foundation of mechanical research and application of these materials. In this article, a finite element method (FEM) of filamentwound composites is developed which is based on the micro stiffness model of a filamentwound composite. The micro stiffness model is based on Fourier series. The micro stiffness is brought into FEM through a mapping relation between the micro stiffness field and macro structure. Anisotropic element is used in this method. No complicated treatment on geometrical modeling and meshing is needed. The flow chart of this method is first established, and MATLAB is used for developing a program for the micro stiffness model. The APDL language is used for developing the program of geometrical modeling, meshing, and inputting material properties, etc. Finally a numerical example is analyzed. The result of the example shows that the stress and strain of every layer is in periodical distribution, and that the local stress is amplified by the undulation of the fiber. Direction shifting of the fiber causes shear stress shifting, and the reduction of local stiffness causes the local strain to be larger than the average strain. Compared with traditional methods, the application of micro stiffness in FEM can better indicate the effect of micro structure on stress and strain.

Key words: filament, composites, finite element method, micro stiffness, structural analysis

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