柔性飞艇主气囊干湿模态分析与影响因素  

Dry and Wet Modal Analysis and Evaluation of Influencing Factors for Flexible Airship Envelop

作　　者：陈宇峰[1] 陈务军[1] 何艳丽[1] 张大旭[1] 

机构地区：[1]上海交通大学空间结构研究中心,上海200240

出　　处：《上海交通大学学报》2014年第2期234-238,243,共6页Journal of Shanghai Jiaotong University

基　　金：国家自然科学基金项目(51278299)资助项目

摘　　要：为了掌握柔性飞艇无约束状态下的模态特性,以25m平流层验证飞艇为基本分析对象,对其自振特性进行研究.根据充气膜结构的力学特点,基于柔性飞艇主气囊初始形状,通过充气压力静力非线性分析得到充气平衡形态位形和应力,利用兰索斯法进行模态数值分析.分析表明,影响柔性飞艇模态特性的主要因素为:壳单元与膜单元模型、拼接缝、不均匀质量分布、内外压差、尺寸、飞艇周围空气附加质量,且最后三者为重要影响因素;壳单元和膜单元模型频率相近且振型一致.对柔性平流层飞艇结构设计具有参考价值.In order to grasp the unconstrained modal characteristics of the flexible airship envelop, the natural vibration performance was investigated thoroughly for a 25 m long stratospheric demonstration airship. The flexible airship envelop features is a free-floating inflatable membrane structure. Based on the mechanical nature of pneumatic-stressed membrane structures, the deformed equilibrium shape and stress were computed from the initial geometry configuration, subjected the inflated air pressure through nonlinear structural analysis. The block Lanczos method was employed for modal analysis. The main influencing factors were evaluated thoroughly for modal behavior, including shell element and membrane element, pressure, geometry size, weld seam, non-uniform distributed mass and the added atmosphere mass. The numerical models of membrane and shell element have close natural frequency and identical modal shape. The air-added mass, pressure and geometry size are the key factors to govern the modal performance. This paper can provide reference for structural engineering design of stratospheric airship.

关 键 词：平流层飞艇 主气囊 干模态 湿模态 空气附加质量 

分 类 号：V274[航空宇航科学与技术—飞行器设计]