直升机复合材料吸声结构制造技术及性能研究

Research on Manufacturing Technology and Acoustic Performance of Composite Sound Absorbing Structure for Helicopter

本文直升机复合材料吸声以单自由度降噪蜂窝夹层结构为研究对象,开展了吸声理论研究,根据直升机舱内噪声特点对微穿孔板孔径、穿孔率等进行结构参数设计。通过微穿孔板制孔技术、热破胶膜制孔技术、胶接技术等制造技术研究,完成复合材料吸声结构试验件制造,验证了微穿孔板和蜂窝热破胶膜制孔效果良好,且破孔率均为100%;采用两种方案进行试验件胶接,胶接后通孔率98%以上,满足预期要求;采用胶接方案1平面拉伸强度更高,更适用于直升机复合材料吸声结构件制造。在入射频率1600-3600 Hz频率段内,该结构的垂直入射吸声系数在0.5以上,说明对直升机主减/发动机舱声场吸声效果较好。研究结果可对未来直升机减振降噪用复合材料构件研制提供有益参考。

In this paper,the research object of helicopter composite sound absorption is single degree of freedom noise reduction honeycomb sandwich structure.This paper conduct theoretical research on noise absorption and parameter design of micro perforated plate aperture,perforation rate,etc.according to noise characteristic of helicopter cabin,and complete the manufacturing of composite sound absorbing structure test pieces through some key technology research.A good effect has been verified on the hot break adhesive film of micro perforated plate and honeycomb,with hole breaking rate of 100%.Two schemes were used for bonding the test piece,with a through-hole rate of over 98%,meeting the requirements.The plane tensile strength of bonding scheme 1 was higher,making it more suitable for manufacturing composite sound absorbing structure components.The vertical incident sound absorption coefficient of this structure is above 0.5 in the frequency range of 1600-3600 Hz,which indicating that this structure has a good sound absorption effect on the main reducer and engine compartment sound field of helicopter.The research results can be beneficial for helicopter vibration and noise reduction in the future.