纤维增强复合材料轴结构铺层方案优化设计

Optimization design for laminate scheme of fiber reinforced composite shaft

基于细观力学有限元法,采用改进的细观力学代表体积元(RVE)模型预测连续纤维增强金属基复合材料力学性能,对比分析相同体积分数下不同排列RVE模型的计算结果.选定连续纤维增强金属基复合材料轴结构为研究对象,建立连续纤维增强金属基复合材料轴结构细、宏观力学模型,开展该轴结构承载能力计算.在此基础上,为实现连续纤维增强金属基复合材料低压涡轮轴铺层方案优化设计,参照某型航空发动机设计要求,以总铺层厚度为目标函数,采用random design法,确定了由细观RVE排列结构至宏观轴结构铺层方案.结果表明:采用正方形对角排列RVE模型计算的力学性能优于四边形排列RVE模型;纤维与基体呈正方形对角排列可提高轴结构承载能力、临界屈曲载荷、临界转速;该方法确定的铺层方案与通用(GE)公司的SiC/Ti低压涡轮轴铺层方案一致.

Based on micro mechanics finite element method, the improved micro mechan- ics model of the representative volume element （RVE） was used to predict effective mechani- cal properties of continuous fiber reinforced metal matrix composite. Then square diagonally arranged RVE model was used to calculate its mechanical performance, which was better than that of quadrilateral RVE model. Taking continuous fiber reinforced metal matrix composite shaft as research objects, a micro and macro mechanics model of continuous fiber reinforced metal matrix composite shaft was built. The carrying capacity of this shaft, the rule of shaft carrying capacity, critical buckling load, and critical speed under the influence on different arrays between fiber and matrix were calculated. On this basis, in order to achieve optimization design about laminate scheme of continuous fiber reinforced metal matrix composite shaft, total thickness was taken as objective function with design condition of an aero-engine, and laminate scheme from micro RVE to macro shaft was obtained by random design method. Result shows that, use square diagonally arranged RVE model to calculate the mechanical performance is better than that of quadrilateral RVE model. Fiber and matrix is square diagonally arranged shaft carrying capacity, the critical buckling load and critical speed can be improved. The scheme is the same as GE （General Electric） Company SiC/Ti low pressure turbine shaft layer solution.