发动机半正弦波脉冲冲击下固体火箭动力倒飞和软着陆时的位移响应

Displacement Response of Inverse Flight with Dynamic Force and Soft Landing in Solid Rocket Under Half Sinusoidal Wave Impulse Shock

针对现有固体火箭位移响应未完整求解的情况,对延迟时间进行杜阿迈尔卷积定积分,可推导出固体火箭的位移响应。将火箭在动力倒飞及软着陆的位移响应和发生时间进行逐一比较,获得位移冲击谱和最小发生时间。研究结果表明:在动力倒飞阶段,无量纲的火箭位移响应不会恒等于0。在软着陆阶段,无量纲的火箭位移响应有可能恒等于0;当脉冲冲击持续时间较短时,火箭位移响应最大值发生在冲击作用结束以后的软着陆阶段;当脉冲冲击持续时间较长时,火箭位移响应最大值发生在冲击作用范围内的动力倒飞阶段;火箭的位移达到最大值时,相应的发生时间不是唯一的,存在多个发生时间使位移取得最大值;火箭位移响应最大值的计算结果与实验数据之间的相对误差为-9%~7%,火箭位移最大值发生时间的计算结果与实验数据之间的相对误差为-6%~8%。

Aiming at the problem that current displacement response of solid rocket has not been completely solved,the displacement response of solid rocket is deduced from Duhamel convolutional definite integral on the retardation time.The displacement shock spectrum and minimum happening time are obtained after the displacement response and happening time of rocket in inverse flight with dynamic force and soft landing are compared.The research results show that the dimensionless rocket displacement response cannot permanently be equal to zero in inverse flight stage with dynamic force,but in soft landing stage,this phenomenon may occur.The maximum rocket displacement response happens in soft landing stage after shock action when shock impulse duration is relatively short,and it happens in inverse flight stage with dynamic force during shock action when the shock impulse duration is relatively long.When rocket displacement achieves the maximum value,the corresponding happening time is not sole and there are several happening times making displacement attain the maximum value.The relative error between the calculating result of rocket displacement response’s maximum value and the experimental data is in the range of-9%-7%.The relative error between the calculating result of happening time of rocket displacement’s maximum value and experimental data is in the range of-6%-8%.