基于冲击响应谱变换的星箭力学环境等效频谱影响因素分析

介绍基于冲击响应谱变换和稳态放大系数的星箭力学环境等效频谱工程计算方法，给出冲击响应谱相对于正弦基础激励的瞬态放大系数近似解析公式，并结合典型星箭界面加速度时域响应数据分析力学环境等效频谱的影响因素。数值计算和理论分析结果表明：发射段低频力学环境瞬态效应明显，采用工程计算方法确定星箭力学环境等效频谱的结果受稳态放大系数取值影响较大——该系数取值的增大将使等效频谱幅值在整体上明显减小，频率分布特性也会发生变化。可见，目前工程上所采用的星箭力学环境等效频谱计算方法尚有不合理之处，后续应探索新的星箭力学环境等效频谱确定方法。

Analysis of the influencing factors of equivalent frequency spectra of mechanical environment for SC/LV interface based on shock response spectrum transformation

Based on the traditional engineering approach of calculating the equivalent frequency spectra by the shock response spectrum transformation and using the steady-state amplification factor, an approximate formula for determining the transient amplification factor is presented in this paper for the impact response spectrum relative to the sinusoidal base excitation. Then the influencing factors of the equivalent frequency spectra of the mechanical environment are analyzed with an example of the typical time-domain shock response on the interface between the spacecraft and the launch vehicle. It is shown both by theoretical and numerical analyses that the transient effects of the dynamic loads during the launch phase are so evident that they cannot be accurately symbolized by the traditional approach, since the equivalent frequency spectra change significantly with the Q value, and the spectrum amplitudes are decreased when the Q value increases. Therefore, it can be concluded that the current engineering approach to calculate the equivalent frequency spectra of the mechanical environment for satellites and launch vehicles remains to be improved by more reasonable solutions in the future.