空投装备气囊缓冲系统评价方法

Research on Assessment Method of Airbag Cushion System for Airdropping Equipment

以热力学理论和有限元法为基础,建立装备-气囊系统有限元模型,并利用试验数据对模型进行验证。对比结果表明,所建模型系统的精度较高,可以用在下一步的仿真分析工作中。针对缓冲气囊的复杂非线性模型计算规模大、难以进行大规模计算的问题,以着陆初速度、初始侧倾角、初始俯仰角、横向速度和地面坡度为变量,分别以最大冲击加速度、最大侧倾角、最大俯仰角以及气囊最大内压为响应,结合扩展拉丁超立方设计,采用径向基函数构建多工况响应代理模型。考虑空投装备在着陆过程中环境因素以及空投装备着陆姿态的影响,利用蒙特卡罗法结合代理模型对多工况下的空投装备着陆成功概率进行计算。通过计算得到着陆成功概率为95.84%,冲击加速度为其主要影响因素,气囊内压为次要因素。

Based on thermodynamics theory and finite element method, a finite element model of equipment and its airbag cushion system is established and verified experimentally. The simulation results are obtained under the same conditions of the airdrop test and the simulation results agree very well with the experimental results, which indicate the established model is valid for further research. Because nonlinear model of airbags cushion system is very complicated, the calculation takes tens of hours of CPU time. As a result, the large-scale calculation is impossible. In order to overcome this problem, surrogate models are employed instead of the complex finite element model based on extended latin hypercube method and radial basis function. Initial velocity, initial heeling angle, initial pitch angle, lateral velocity and gradient are variables, while maximum acceleration, maximum heeling angle, maximum pitch angle and maximum airbag pressure are responses. Considering the influence of landing condition, Monte Carlo method and surrogate model are used to calculate landing success probability of airdropping equipment under multi-condition. The landing success probability calculated is 95.84%. Acceleration is the primary contributor to cushion performance, while pressure inside airbag is secondary contributor.