三维编织复合材料弹性性能数值预测及细观应力分析

Prediction of elastic constants and simulation of stress field of 3D braided composites based on the finite element method

基于考虑纤维束面接触的细观结构模型,引入周期性位移边界条件,采用细观有限元方法建立了材料的弹性性能预报模型。模型数值结果与试件实测数据吻合较好,证明了该模型的合理有效性。经详细分析单胞在典型工况载荷作用下的细观应力分布及变形,表明模型体现了周期性相邻单胞表面力和位移的连续性,能获得单胞更为合理的细观应力应变场。

Based on the microstructure model established by the authors, coinciding with the actual configuration of braided composites, a model to predict the elastic properties was proposed by using the 3D FEM, coupled with the periodical boundary conditions. The calculated values by the model well agree with the measured values. Numerical results verify the effectiveness of the model. The stress and strain fields of the model under such typical load cases as tension and shear were analyzed in detail, respectively. The results indicate that the application of the periodical boundary conditions guarantees the continuities of the traction and displacement on the parallel boundary surfaces of the cubic model. Therefore, the stress field and the strain field obtained by the model are more reasonable than by the existing FEM models.