基于正弦基础激励的航天器结构模型修正方法

正弦振动试验是航天器系统级和单机产品需要开展的常规试验,充分利用工程中积累的正弦试验数据进行结构模型修正具有重要的工程意义。文章首先介绍了基础激励下结构模型修正方法,通过矩阵分块、待修正参数归一化、参与修正的频率点选择等步骤,推导出基于基础激励的模型修正公式;然后对国际通用算例GARTEUR桁架结构的有限元模型进行修正,分析修正后模型在修正频段内和修正频段外计算所得模态频率,验证修正后模型对模态频率的复现和预示能力,通过对比试验模型、分析模型和修正后模型中4个典型节点的响应曲线,检验修正后模型精度。结果表明:修正后模型的模态频率和响应曲线均与试验模型趋于一致,证实了该修正方法对GARTEUR结构修正的有效性。

Spacecraft Structure Model Updating Method Based on Sine Base Excitation

Sine vibration test is widely used in spacecraft system-level and component-level tests; making full use of the accumulated test data plays an important role in model updating process. The base-excitation-based model updating method is introduced through matrix reduction, param- eter to be updated unitary and updating frequency point selection, and then the GARTEUR truss model is updated, the reappearance and prediction ability of the modal frequency in and out of the updated frequency range are analyzed and the updated precision of the response curves of the four classic nodes in the test model, and the analysis model and the updated model are compared with each other. The results show that the updated model frequency and response curve are close to those of the test model, and the validity of the updating method is approved.