基频降低对火箭点火起飞动响应的影响分析

Dynamic Response Analysis of Launch Vehicle with Reducing Payload's Fundamental Frequency

为了分析有效载荷基频降低对火箭发射时箭体的动响应的影响规律,将不同的有效载荷基频引入到运载火箭纵向有限元模型中,通过改变有效载荷基频,计算箭体在发射阶段受到冲击载荷时的瞬态动力学响应,并找出有效载荷以及星箭界面处随发动机推力变化的加速度、单元力等响应时程的变化规律。结果表明:有效载荷基频降低对发射时箭体的动响应有一定影响,有效载荷位置的加速度响应受到的影响较为明显,有一定程度地增加,其对星箭界面处载荷的影响则较小。

In order to analyze the effect law of dynamic response when launch a rocket by different payload＇s fun damental frequency, different fundamental frequencies are led to the launch vehicle＇s longitudinal model. By changing the frequency, vehicle＇s dynamic responses are analyzed with finite clement method and the acceleration/element force response on payload wilh the changing of jet thrust is calculated. It shows that the fundamen tal frequency affects the dynamic response of the launch vehicle. The effect on the acceleration response of payload is more palpable than the other parts.