中文摘要：

双层圆柱壳体机械噪声源众多,噪声数据结构复杂。使用相关性分析研究实验测得的壳体机械噪声数据,并使用主成分分析法（PCA）对噪声数据进行降维处理。验证了使用累积贡献率大于0.85作为双层圆柱壳体机械噪声选择主元数目标准的合理性。初步分析噪声源在不同区域的传播特点以及不同工况下的噪声源与其在不同通道上降维后所保留主元数目的关系。

英文摘要：

Ribbed double-layer cylindrical shells have many mechanical noise sources,and the noise date is very intricate.In this paper,the noise date of the cylindrical shell is studied using the relativity analysis method.And the dimension-reduction processing of the noise date is also carried out using the PCA method.After summarizing some specific steps of dimension reduction,the relation between the mechanical noise sources and the principal components（PCs） in different sensors is analyzed.Results show that it is reasonable to select these mechanical noises,which accumulated contribution ratios are larger than 0.85,as a standard for determination of the number of principal components.