公路运输环境下运输车及导弹固体发动机响应数值分析

Numerical Analysis of Vehicle and Missile Solid Rocket Motor Response under Road Transportation Environment

为解决某型固体火箭发动机在公路运输过程中动力学响应难以直接测定的实际问题,构建了运输车的13自由度动力学模型,采用谐波叠加法模拟路面不平度激励后,基于达朗贝尔原理计算得到车身质心处的时域响应,并简要分析了不同运输工况下响应规律,最后利用MSC.Nastran分别仿真计算了发动机在加速度载荷及其与温度载荷联合作用下的动力学响应。结果表明:运输过程中,车身质心处加速度响应近似服从高斯分布,且其均方根值随运输速度提升或运输公路等级下降而呈非线性增加趋势;考虑随机振动与温度载荷联合作用时,发动机壳体von Mises应力响应最大值超过500 MPa,药柱von Mises应变大于5%,均高于振动载荷单独作用响应,但不会造成发动机强度破坏。

In order to solve the problem that it is difficult to measure directly the dynamic response of a solid rocket motor in the process of road transportation,a 13-degree-of-freedom full vehicle dynamic mo del is built,and after obtaining the road random roughness by harmony superposition method,the time domain dynamic response at the mass center of carriage is calculated based on Darren Bell principle,then the response law is analyzed roughly. The responses of solid rocket motor model under acceleration load and under combined action of temperature load and acceleration load are simulated respectively by MSC.Nastran. The results show that in the process of transportation,the acceleration response at the center of mass approximately obeys the Gaussian distribution,and its root mean square value increases nonlinearly with the increase of transportation speed or the decrease of transportation road grade. When considering the combined action of random vibration and temperature load,the maximum stress response of the engine case von Mises is more than 500 MPa,and the strain of propellant von Mises is more than 5%,both of which are higher than the response of the vibration load acting alone,but will not cause the strength failure of the engine.