基于遗传算法的飞机复合材料结构装配压紧力大小与布局的优化基于遗传算法的飞机复合材料结构装配压紧力大小与布局的优化

针对飞机复合材料结构装配时出现间隙的问题，考虑用压紧力消除间隙可能引起层合板产生损伤，提出了基于遗传算法的压紧力大小和布局的优化算法。结合有限元分析方法，考虑压紧机构之间的干涉问题，以复合材料分层损伤为约束条件，以间隙消除率为优化目标，建立了压紧力大小和布局的优化模型。以复合材料翼盒为例，建立基于内聚力单元的有限元模型，使用上述方法优化复合材料壁板上的压紧力大小和布局。将优化后得到的压紧力方案在有限元模型上进行验算，计算间隙消除率并分析应力应变状态和分层损伤情况。结果表明，优化后的方案能够在不使壁板产生分层损伤的前提下提高间隙消除率，并且能够使壁板的应力和应变分布趋于均匀。当装配间隙的初始值为0.2~0.8 mm时，优化后的方案使间隙消除率提高至77.4%~100%，比优化前的方案提高了19.2%~177.8%。 

Optimization of size and layout of pressing force for composite airframe structure assembly based on genetic algorithm

For the assembly gap in composite airframe structure, an optimization method based on genetic algorithm was proposed to optimize the size and layout of pressing force, in which damage caused by pressing force was considered. Combining with finite element analysis, considering the interference between pressing points, with laminates delamination as the constraint condition and elimination rate of gap as the objective function, the optimization model with size and layout of pressing force was established. Taking composite win box as an example, establishing finite element model based on cohesive element, the optimization method was applied to optimize pressing force on composite panel. Then, with the optimum size and layout of pressing force, the elimination rate of gap, delamination damage, stress and strain were calculated and analyzed. The results demonstrate that:the optimum pressing force makes stress and strain distribution more uniform; elimination rate of gap is improved dramatically compared with the traditional one without laminates delamination. When the initial assembly gap is 0.2-0.8 mm, the elimination rate of gap is increased to 77.4%-100%, which is 19.2%-177.8% higher than that before the optimization.