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- 2016
超大口径天线结构的风振响应
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Abstract:
为明确大型天线结构风振响应特性,以待建的110 m全可动天线为研究平台,对其展开各迎风姿态下的风荷载特性分析。根据刚性模型风洞试验结果,探讨了反射面平均风压分布规律及最不利风向角。在此基础上,采用基于随机振动理论的非线性时程分析法进一步对结构的风致动力响应展开研究,总结了风振响应特性。结果表明,该结构自振频率分布密集,结构较柔,其风振响应是一个窄带过程,振动能量随着俯仰角的增大而逐渐提高,且高阶振型逐渐对风致振动有所贡献。该成果可为天线结构抗风设计提供较为全面的荷载取值参考。
In order to grasp the wind-induced dynamic characteristics of large antenna structures, a 110m fully steerable radio telescope to be built is used as a study platform and selected as the research object for various kinds of upwind profiles. Based on the wind tunnel test results of a rigid model, wind distribution characteristics of the reflector and the unfavorable wind angle are analyzed and discussed. On this basis, the nonlinear time-history method based on random vibration is used further analyze the wind-induced dynamic characteristics of the structure, and the wind vibration response features are summarized. The results indicate that the structure has a dense natural frequency distribution and is more flexible. Its wind vibration response is a narrow-band process. As elevation gradually increases, not only does the vibration energy increase, but the higher modes also contribute progressively to wind-induced vibration. The achievements above provide a more comprehensive wind load value reference for the telescope structure in its wind force proofing design.