湿热环境对复合材料蜂窝板振动特性的影响

Effect of hygrothermal environment on vibration characteristic of composite honeycomb structure

为了研究复合材料蜂窝板在湿热环境下的振动特性,针对由碳纤维/双马来酰亚胺复合材料层合板和Nomex芯层复合而成的蜂窝板进行了不同温湿度下固有频率的数值分析。基于分段剪切变形理论,分别考虑复合材料蜂窝薄板和厚板两种情况,利用湿度与温度的等效性,求解了复合材料蜂窝板的振动特征方程。利用有限元软件ABAQUS,建立了四端固支的复合材料蜂窝板精细化模型。分别讨论了温度、湿度、温湿度联合作用对复合材料蜂窝薄板和厚板固有频率的影响。结果表明:相比于温度的升高,复合材料蜂窝板固有频率对吸湿量的增加更为敏感;相同的湿热环境下,复合材料蜂窝厚板结构的固有频率比薄板结构大,且阶次越高,固有频率上升的幅度越大;温湿度的联合作用比它们单独作用的叠加对复合材料蜂窝板固有频率的影响更大,且在复合材料蜂窝薄板中更加明显。

In order to study the vibration characteristic of composite honeycomb structure under hygrothermal condition,the natural frequencies of honeycomb structure composed by carbon fiber/bismaleimide composite laminate and Nomex core were numerically analyzed under different temperatures and humidities.Based on the piecewise shear deformation theory,considering the honeycomb thin plate and thick plate respectively,the eigenvibration equation of composite honeycomb structure was solved by finite element method using the equivalence of temperature and humidity.A detailed model of composite honeycomb structure with four-edge clamped support was established by using finite element software ABAQUS.The effects of temperature,humidity,and combined temperature and humidity on the vibration characteristic of composite honeycomb thin plate and thick plate were discussed respectively.The numerical results show that compared with the increase of temperature,the natural frequencies of honeycomb structure are more sensitive to the increase of moisture concentration.Under the same humid and thermal environment,the natural frequency of the thick plate structure is larger than that of the thin plate,and the higher order of natural frequency,the greater the increase of natural frequency.The coupling effect of temperature and humidity has a greater effect on the natural frequency of composite honeycomb structure than the superposition of temperature and humidity when they act alone,and this effect is more obvious for the composite honeycomb thin plate.