重复使用火箭着陆缓冲的机构冲击动力学分析及实验验证

为描述运载火箭着陆引起的着陆缓冲机构横向振动, 提出一种等效模型, 将着陆引起的激励等效为冲击激励和稳态激励的叠加。采用假设模态法求解着陆缓冲机构的横向振动模态, 并考虑轴向力与横向振动的耦合, 进一步通过模态叠加法求解振动响应, 得到由着陆冲击引起的着陆缓冲机构横向振动的半解析解。基于真实产品进行的垂直着陆冲击实验结果表明, 该模型可较精确地描述着陆缓冲机构横向振动的响应和最大弯矩。基于该模型, 分析着陆缓冲机构的构型参数和材料强度对着陆缓冲机构的影响, 研究结果可为实际工程相关着陆缓冲机构的参数设计提供指导。

Dynamic Analysis of Touchdown Impact for the Landing Gearof Reusable Launch Vehicle and Experimental Evidence

In order to describe the lateral vibration of the landing gear caused by landing of launch vehicle, an equivalent model for the excitation of landing impact is proposed. In this model, the excitation is equivalent to the superposition of impact excitation and steady excitation. Secondly, the bending vibration modes of the landing gear are established by the assumed mode method, where the coupling term of the longitudinal deformation caused by transverse deformation is included in the expression of bending vibration. The dynamic response, excited by the landing impact, is solved by the mode superposition method, so as to obtain a semi-analytical solution for the problem. The real product experiments of vertical landing impact show that the proposed model is able to accurately describe the lateral vibration and maximum moment of the landing gear. Finally, we analyze how the parameters of the configuration and strength of materials affect the landing gear using the proposed model. The result can guide the parameter design of the landing gear in the engineering implementation.