基于区域叠合技术的三维编织复合材料渐进损伤过程数值模拟

基于区域叠合技术（DST）对编织复合材料渐进损伤过程进行了分析，利用ANSYS参数化设计语言建立了参数化的编织件模型，应用单元切割法在单元边与切割面交点处增加新的节点，将新增节点与该单元部分其他节点重构单元，实现从编织件模型中切割出增强相单胞模型。分别利用Hashin准则与Von Mises准则判断增强相损伤和基体损伤，根据相应损伤模式按修正的Blackketter刚度退化方案对材料刚度进行退化，应用适用于损伤分析的刚度匹配方法，实现区域叠合技术在编织复合材料渐进损伤分析中的应用。提出损伤结果映射方法，实现了基于区域叠合技术所建基体模型的渐进损伤过程的结果显示。数值分析结果发现，区域叠合法分析结果与传统方法分析结果一致，且强度和断裂应变预测结果与试验结果相吻合。

Simulation of progressive damage of 3D braided compositesusing domain superposition technique

Domain superposition technique (DST) has been implemented for simulation of the progressive damage of braided composites in this paper. To establish the tow finite element mesh used for the DST analysis model, first of all, regular parametric geometric model for the tows were easily constructed using ANSYS parametric design language (APDL), and then a programmed automatic mesh trimming process has been carried out to trim the tow meshes established in the first step to establish new tow meshes which can fit exactly the space of the unit cell (UC) model used for the DST analysis. The element edges crossing the UC boundaries were cut by the UC boundaries to create new nodes. Some new elements were constructed using these newly created nodes and some original nodes to fit the boundary regions. Hashin and Von Mises damage criterions were used to predict damage initiations in tow phase and matrix respectively. Blackketter's degradation scheme for the elastic properties of the composites was adopted. A stiffness matching scheme suitable for damage analysis for DST implementation has been applied. A domain mapping method to ease the post-processing of the damage results of the matrix/resin-rich regions has been implemented. The numerical results predicted using the DST model correlate well with the traditional FEM predictions. And also, the strength and failure strain predictions are in good agreement with experimental results.