运载火箭飞行载荷测量与分析

Launch Vehicle In-flight Loads Measurement and Analysis

为获取运载火箭结构在飞行过程中准确的截面动态载荷,基于应变测量原理设计了一套飞行载荷测量系统,通过多向载荷标定试验获得结构的灵敏度矩阵,采用非线性载荷模型将飞行过程测量的应变响应转换为截面的动态飞行载荷。在某型号中首次开展了运载火箭飞行载荷测量工作,获得了二级箱间段和有效载荷支架在整个飞行过程中的轴向力、弯矩载荷,并与飞行时序、地面模态试验结果进行了详细对比,结果表明:2个部段的飞行载荷数据质量良好,飞行载荷有变化的时段均与飞行时序对应,并与过载的遥测结果趋势一致,同时也发现了多项飞行动态载荷的特点,为载荷设计提供了数据支撑,有助于后续型号的优化与改进设计。

In order to obtain the exact in-flight dynamic loads of a launch vehicle,a measurement system is designed which is based on strain measurement principle.Through multiple load calibration tests,the relationship between load and strain is obtained.Through a nonlinear fit model,strain data measured during flight are diverted into structure load.The system is loaded on a certain launch vehicle for the first time in China,and the in-flight loads of two components are obtained,including axial load and bend load.Comparison between in-flight load and flight schedule as well as modal test results are made.Results show that the load data satisfies the requirement.The characteristic points of in-flight loads are highly related to flight sequence,and also meet with modal test results.Some characteristics of non-static loads are discovered.The results are helpful for load design and the improvement of following types.