声致振动下铝板的实验模态分析与参数辨识

EMA of an aluminum plate under sound-induced excitation

对于大型航天器的太阳能帆板,在自由-自由悬挂条件下,由于结构本身的超低频、大位移和局部模态丰富等特点,常规的激励方式有着各种各样的缺点,如:模态识别结果置信度降低,局部模态占优,系统稳定性差等。基于这些困难,针对大型航天器的太阳能帆板的模态分析试验背景,提出一种非接触式声致振动激励方法,设计并构造了矩形铝板承受扬声器激励的实验模型和参数辨识算法,针对实测响应数据进行模态分析,并将其与传统激励方式下的模态分析结果进行对比。该结果对太阳能帆板等大型航天器的模态实验设计与参数识别具有指导意义。

For large solar panels of spacecraft in a free-hanging conditions, as a result of the structure＇s ultra-low frequency, large displacement and dense local modes, the conventional approach has inspired a variety of shortcomings, such as： low MAC and poor system stability. Based on these difficulties and in the context of modal test for large solar panels of spacecraft, this paper puts forward a non - contact sound-induced exciting method. Meanwhile, the paper designs and construct an experimental modal test, in which a rectangular aluminum plate is excited by a speaker, and the modal parameters are identified. At last, the results are compared with ones identified by traditional methods. The results provide a guiding significance for the experimental design and identification of solar panels and other large spacecrafts.