气囊硬度对固化后帽型长桁厚度的影响

为满足宽体客机机身轻质高强的要求，机身复合材料蒙皮需要长桁的支撑以提高复合材料壁板的刚度。为获得厚度均匀性良好的帽型长桁加筋壁板，对帽型长桁加筋壁板成型工艺中真空袋囊芯模的方法进行了改进，提出了一种硅橡胶囊芯模与真空袋囊芯模相结合的方法，获得了厚度均匀性良好的帽型长桁壁板，满足机身复合材料帽型长桁-蒙皮共固化成型时尺寸精度的要求。利用有限元仿真方法，研究了硅橡胶囊芯模截面尺寸、硅橡胶材料属性对长桁厚度均匀性的影响，结果发现所用硅橡胶囊芯模硬度越大，长桁尺寸均匀性越差。不同条件下所得长桁厚度对理论分析的准确性进行了验证。考虑硅橡胶硬度对长桁尺寸均匀性及工艺操作性的影响，最终选定所用硅橡胶气囊硬度为50HA，所得蒙皮-长桁实际测量的平均厚度与理论厚度偏差小于6%，细观分析发现蒙皮-长桁连接处纤维走向没有发生变形。

Effect of airbag hardness on thickness of hat-shaped stringer

To obtain the hat-stiffened stringer wall plate with high quality, the forming method of vacuum bag core mould is improved. This paper presents a method to combine the silicon rubber core module with the vacuum core module, obtaining the hat-shaped stringer wall plate with high surface quality. It meets the requirement of dimension accuracy of composite hat-shaped stringers-skin with co-curing molding. Using the finite element simulation method, this paper studies the influence of the size of silicon rubber core mould and the properties of silicon rubber material on the thickness uniformity of stringer. The results show that the harder the core mold is, the less uniform the stringer is. The accuracy of the theoretical analysis is verified by the stringer thickness obtained under different conditions. Taking the influence of silicone rubber hardness on the uniformity of stringer dimension and process operation into consideration, finally, 50HA is selected as the hardness of the silicon rubber, and the measured average thickness of the skin-stringer deviates less than 6% from the theoretical thickness. The microanalysis shows that the fiber trend of the connection between skin and hat-shaped stringer has no deformation.