基于三维动力学模型及试验数据重用技术的全箭模态分析

目的在运载火箭设计过程中,获得精确的全箭模态数据,为火箭总体设计提供关键输入参数。方法针对全箭动特性数据的高效高精度获取问题,提出并实践基于三维动力学模型和试验数据重用相结合的模态参数获取方法,包括高精度全箭三维动力学模型建模技术、数据重用技术、多状态模型修正技术、模型综合技术。结果解决了界面连接刚度未知条件下的全箭模态精确预示难题。在设计阶段给出了高精度的动特性数据,分析结果与靶场试验结果比对,一阶弯曲频率误差在2%以内,斜率误差在4%以内,分析结果通过了靶场竖立模态试验验证,最后进一步通过型号首飞成功验证。结论靶场竖立模态试验验证和型号首飞成功验证说明提出的获取全箭动特性参数方法高效可靠。

Modal Analysis of the Whole Launch Vehicle Based on Three-Dimensional Dynamic Numerical Model and Test Data Reuse Techniques

Obtaining accurate modal data of the whole launch vehicle can provide the key input data in the overall design. In order to solve the problem of obtaining high-efficiency and high-precision of dynamic characteristic data of the whole launch vehicle, an acquisition method of modal parameters, integrating the three-dimensional high-precision dynamic numerical model, reuse techniques of test data, multi-state model updating method and model synthesis method, is proposed and practiced on the basis of the model synthesis theory and test data. Under the premise of unknown interface connection stiffness, the high-precision modal parameters of whole launch vehicle is predicted, and the high-precision dynamic characteristic data is given during the design process of vehicle. The error between the numerical analysis results and the test results is less than 2% in first-order bending frequency, and less than 4% in first-order bending slope. Moreover, the numerical results are in good agreement with the verification results of range vertical modal test and the first-flight test. With the verification of range vertical modal test and the first-flight test, the virtual-real combination method proposed in this paper can obtain the dynamic characteristic parameters of whole launch vehicle efficiently and reliably.