大尺寸金属埋件与碳纤维蒙皮蜂窝夹层结构热膨胀匹配研究

Research on Thermal Expansion Matching of Large-scale Metal Embedded Parts and Carbon Skin Honeycomb Sandwich Structure

作为卫星重要结构件,含铝合金埋件的碳纤维蒙皮蜂窝夹层结构成为卫星减重的热点研究对象。由于大尺寸铝合金埋件与碳纤维蒙皮热膨胀系数差异大,蜂窝夹层结构固化后,易致使蒙皮开裂,成为该项技术推广应用的难点。本文采用有限元分析法对降温过程中由于金属埋件收缩蜂窝夹层结构产生内应力进行计算,发现蒙皮因厚度减薄导致的强度不足是开裂的主要原因,再结合分析计算和对比试验验证,最终确认在铝合金埋件和碳纤维蒙皮之间添加0.5 mm厚高强碳纤维编制布过渡层可以有效解决开裂难题,为蜂窝夹层结构设计优化提供技术支撑。

As an important satellite structural component,the carbon-skinned honeycomb sandwich structure with aluminum alloy embedded parts becomes a hot research problem of satellite weight-loss.Because of the large difference in thermal expansion coefficient between the large-sized aluminum alloy embedded parts and the carbon fiber skin,in the molding process,the product is easy crack,which becomes the difficulty of popularization and application for this technology.In this paper,the finite element analysis method was used to calculate the internal stress generated by the honeycomb sandwich structure due to the shrinkage of the metal embedded parts during the cooling process.It was found that the lack of strength due to the thickness reduction of the skin was the main reason for cracking.It was confirmed that the addition of 0.5 mm high-strength carbon fiber cloth transition layer between the aluminum alloy embedded parts and the carbon skin could effectively solve the crack problem and provide technical support for the structural optimization of the honeycomb sandwich structure.