基于遗传算法的复合材料层合板削层结构铺层优化
Ply optimization of composite laminate with ply drop based on genetic algorithm

针对应力变化较大的碳纤维增强复合材料层合板,提出削层结构铺层分级优化模式。通过将结构分解为若干子铺层并对各子铺层的位置、尺寸、铺层数以及铺层顺序进行优化,得到了满足强度和可制造性要求且质量最小的结构设计方案。该模式的第1、2级优化利用参考层对各子铺层位置及尺寸进行优化,第3级优化通过引入3次样条插值参数化方法对各子铺层层数和铺层顺序进行优化。参考层的引入可减少设计变量的数量,3次样条插值参数化方法可解决以铺层角为设计变量时设计变量数目不确定的问题。利用有限元方法对结构进行力学分析计算,并依据Tsai-Wu准则确定结构强度。在第2、3级优化中利用遗传算法对优化问题进行求解。算例计算表明:削层结构铺层分级优化模式结果合理可信。与均匀铺层方法结果比较可知:削层结构可有效减少结构质量。 A hierarchy optimization model was proposed for carbon fiber reinforced polymer laminate with dramatic stress variation. An optimal design with minimal mass was obtained by dividing the structure into several sub-laminates and optimizing the location, size, number of plies and stacking sequences of each sub-laminate with the constraints of strength and manufacturability. The location and size of each sub-laminate were optimized by using the reference ply in the first and second level optimization and the number of plies and stacking sequences of each sub-laminate were optimized by introducing the parametric method of cubic spline interpolation in the third level optimization. The reference ply was designed to reduce the number of design variables and the problem of uncertainty of design variables number was solved by the parametric method of cubic spline interpolation, taking layer angle as design variable. Finite element method was used to analyze the structure mechanically whose strength was judged by Tsai-Wu criterion and genetic algorithm was used in the second and third level optimization to the optimization problem. The example calculation shows that the results of ply hierarchical optimization of ply drop are reasonable and the ply drop can considerably reduce the mass of structures compared with results of uniform layer method.