SiC_p/Al复合材料薄壁结构的动力学特性

Dynamic characteristics of SiC_p/Al composites with thin-walled structure

应用ANSYS有限元分析软件对板类SiC_p/Al复合材料薄壁件的动力学特性进行仿真研究,得到试件厚度、宽度和高度对平板结构薄壁件固有频率的影响规律,以及厚度、凸缘长度和凸缘数对凸缘结构薄壁件固有频率和振型变化的影响规律。平板结构SiC_p/Al复合材料薄壁件固有频率随其宽度和高度的增加而下降,随厚度的增加而增加;其中,薄壁厚度对其固有频率的影响最大,而对其1阶振型影响不大。有凸缘结构薄壁件的固有频率高于平板结构,且随薄壁厚度、凸缘长度和凸缘数的增加而有不同程度的增加;凸缘长度较大时,凸缘个数越多,薄壁件的局部振动越密集;在振动幅度较大的节点处增加较长的凸缘,更有利于提高试件的固有频率,降低凸缘连接处的振动幅度,减小最大振动幅度分布区域,增加极小振动幅度区域。

The dynamic characteristics of SiCJAI composite thin-walled parts were simulated by ANSYS finite element analysis software. The influence laws of thickness, width and height on the natural frequency of thin-walled parts with flat plate structure were obtained. The influences of thickness, flange length and number of flange on the thin-walled parts with flange structure were also obtained. The results show that the natural frequency of thin-walled flat plate parts of SiC^A1 composites decreases with the increase of width and height, but increases with the increase of thickness. Among them, the thickness of thin-walled parts has the greatest influence on their natural frequency, but has little effect on the first-order vibration mode. The natural frequency of the thin-walled parts with flange structure is higher than that of the flat plate structure, and increases to different extent with the addition of flange length and number of flange structure. When the flange length is large, the more the number of flange structure is, the more intensive the local vibration of the thin-walled parts is. Adding the longer flange structure at the node with large vibration amplitude is more conducive to improve the natural frequency, reduce the vibration amplitude at the flange connection, reduce the region of the maximum vibration amplitude, and increase the region of the minimum vibration amplitude.