月球着陆器着陆腿非线性有限元建模与仿真

Nonlinear finite element modeling and simulation for landing leg of lunar lander

为了准确地预测着陆冲击过程中着陆腿的载荷缓冲和吸能性能用于指导着陆缓冲机构的设计和优化,采用非线性有限元方法进行着陆冲击动力学仿真.建立了单腿着陆冲击有限元模型,采用ABAQUS/Explicit显式动力学程序作为求解器.为提高计算效率,采用了质量缩放技术.对2个单腿着陆冲击工况进行了动力学仿真分析,通过与试验数据的对比证明了分析结果的正确性.分析结果表明:非线性有限元模型可以综合考虑各种非线性因素的影响,能较准确地预测着陆腿着陆缓冲性能;着陆腿的弹性对套筒间的摩擦力有较大的影响,增大着陆腿刚度可以减小摩擦力.

In order to accurately predict the load attenuation and energy absorption capabilities of landing leg during the landing event for supporting the design and optimization of landing gear mechanism, a new ap- proach of using nonlinear finite element method in landing impact dynamic analysis was proposed. A detailed finite element model of landing leg was constructed and ABAQUS/Explicit was selected as the solver. Mass scaling technique was used to increase computational efficiency. Landing dynamic simulation of two landing scenarios were carried out, and the validity of analysis results were verified by comparison with test data. Re- suits indicate that nonlinear finite element model with varied nonlinear factors can predict the landing perform- ance of landing leg precisely. The flexibility of landing leg has a great effect on the friction between the inner and outer cylinders of leg struts, and the friction force can be decreased by increasing the leg stiffness.