摘要
对于由复合材料层合板和Nomex芯层构成的含板芯脱胶蜂窝板,进行了不同温湿度下固有频率的数值分析,以探究板芯脱胶对复合材料蜂窝板在湿热环境下固有频率的影响。基于分段剪切变形理论,利用湿热膨胀的等效性,考虑变形后上面板与芯层在脱胶区域处的位移差值,对蜂窝板的运动控制方程进行求解。建立了四端固支的含板芯脱胶复合材料蜂窝板有限元模型。分别讨论了温度、湿度、温湿度联合作用对不同板芯脱胶面积蜂窝板固有频率的影响。算例结果表明:吸湿量在0.5%~0.75%之间时,25%脱胶面积的蜂窝板首先出现了屈曲效应;湿热条件不变时,随着脱胶面积的扩大,复合材料蜂窝板的前三阶固有频率逐渐降低,且对第一阶固有频率的影响最大;当湿热应力达到一定程度时,脱胶面积的增加,会使蜂窝板结构更早地进入湿热屈曲状态,且屈曲效应的影响是从低阶频率逐步扩展到高阶频率;湿、热联合作用下,18%脱胶面积蜂窝板的固有频率受环境的影响最严重。
For the honeycomb structure with facesheet/core debonding composed by composite laminate and Nomex core,numerical analysis under different hygrothermal environment was carried out to investigate the influence of facesheet/core debonding on the natural frequency of composite honeycomb structure.Based on the piecewise shear deformation theory,considering the displacement difference between the upper facesheet and the core in the debonding area after deformation,the governing equation of motion of honeycomb structure was solved by using the equivalence of hygrothermal expansion.Finite element model of composite honeycomb structure with facesheet/core debonding by four-edge clamped support was established.The effects of temperature,humidity and combined humidity and temperature on the natural frequencies of honeycomb structure with different facesheet/core debonding area were discussed,respectively.The results of the example show that when the moisture concentration is between 0.5%and 0.75%,the honeycomb structure with 25%debonding area first appears buckling effect.Under the same hygrothermal environment,with the expansion of debonding area,the first three natural frequencies of composite honeycomb structure decrease gradually,and the influence on the first natural frequency is the greatest.When the hygrothermal stress reaches a certain degree,the increase of debonding area will cause the honeycomb structure to reach the state of hygrothermal buckling earlier,and the effect of buckling will gradually extend from low-order frequency to high-order frequency.Under the combined effect of temperature and humidity,the natural frequency of honeycomb structure with 18%debonding area is most seriously affected by the environment.
作者
王玉鑫
郝彤星
宋昊
卢翔
WANG Yu-xin;HAO Tong-xing;SONG Hao;LU Xiang(Aeronautical Engineering College,Civil Aviation University of China,Tianjin 300300,China)
出处
《复合材料科学与工程》
CAS
北大核心
2021年第2期54-64,共11页
Composites Science and Engineering
关键词
复合材料蜂窝板
板芯脱胶
湿热环境
屈曲
固有频率
composite honeycomb structure
facesheet/core debonding
hygrothermal environment
buckling
natural frequency
