纤维增强复合材料弹性性能预测的域分解方法及应用

提出了新的有限元建模方法,即域分解方法,用于预测纤维增强复合材料单向带T300/BSL914C(环氧树脂)和AS4/3501-6(环氧树脂)的弹性性能。域分解方法基于区域叠合技术,分别建立单胞的整体域与纤维域模型用于代替传统有限元建模方法中单胞的基体域与纤维域模型。整体域是真实基体体积与纤维体积的叠加,两区域网格独立划分,互不影响。采用MSC.Nastran中的多节点约束Explicit单元,在整体域与纤维域节点之间建立位移连接属性模拟单胞基体域与纤维域之间的位移约束关系,从而实现两区域的耦合计算。计算结果表明:域分解方法单胞模型纤维增强方向弹性模量Ez预测值与试验值误差在7%以内,其余弹性常数也都与试验值吻合较好。域分解方法不仅可以大大简化纤维增强复合材料的细观力学建模,而且可以准确地预测纤维增强复合材料的弹性性能。

Prediction of the mechanical behavior of fiber-reinforced composite with domain decomposition method

A new modeling method(domain decomposition method) for finite element analysis is proposed for the prediction of the mechanical behavior of fiber-reinforced composite lamina T300/BSL914C epoxy and AS4/ 3501-6 epoxy.Instead of modeling the fiber and matrix domains in traditional finite element analysis,domain decomposition method based on domain superposition technique separately models the global domain and fiber domain which can be easily discretized by the traditional solid element.Global domain was superimposed by fiber domain and matrix domain.The two domains are superimposed by coupling them with multi-point constraints from commercial finite element package MSC-Nastran.Multi-point constraints established displacement function to simulate coupling between fiber domain and global domain.The numerical results show that the error between elastic modulus E z of fiber-reinforced composite model predicted by domain decomposition method and experimental data is less than 7%,and the rest elastic constants are in good agreement with experimental results.Domain decomposition method can not only greatly simplifies the modeling complexity of fiber-reinforced composite,but also can accurately predict mechanical properties of fiber-reinforced composite.