中文摘要：

薄壁半椭球壳是一种新型的柱胞单元,具有轻质、跨度高、承载能力强等优点。设计了一种以薄壁球壳周期排列作为复合材料芯层的柱胞夹芯复合材料,利用将ANSYS有限元模态分析与模态实验相结合的方法研究其模态特性,发现两者结果吻合较好。利用被验证的模型研究了薄壁球壳的赤道半径（r1）、极半径（r2）、赤道半径/极半径（r1/r2）及壁厚对柱胞夹芯复合材料模态频率的影响规律。研究发现：柱胞夹芯复合材料的模态频率随着球壳单元赤道半径或极半径的增大而增大,随着壁厚的增大而逐渐减小。球壳弹性模量增大到一定值以后,壁厚对频率的影响程度减弱。当r1/r2小于1时,模态频率呈增大趋势,当r1/r2大于1时,模态频率随比值的增大而逐渐减小,即芯层球壳越接近圆形,柱胞夹芯复合材料的固有频率越大。

英文摘要：

The thin-walled semi ellipsoidal shell is a new type of cell element,which has the advantages of light weight,high span and strong bearing capacity. A new sandwich composites which core is periodically arranged in thin-walled shells was designed. The modal characteristics were studied by ANSYS finite element modal analysis combined with modal experiment,and the two results were in good agreement. The influences of the equatorial radius（ r1）,polar radius（ r2）,ratio of the equatorial radius and polar radius of the spherical shell,and the thickness of the thin spherical shell on the modal frequency of sandwich composite were studied based on validated model.The results show that the modal frequency of the column-cell sandwich composites increases with the increase of the equatorial radius and the polar radius of the spherical shell,decreases with the increase of the wall thickness. After the elastic modulus of the spherical shell is increased to a certain value,the influence of the wall thickness on the frequency is weakened. When the ratio of r1/r2 is less than 1,the modal frequency increases,however the ratio decreases with the increase of the ratio when r1/r2 is greater than 1,namely,the closer the core shell is to the circle,the greater the natural frequency of column-cell sandwich composites.