飞机起落架超静定三维复杂机构动力学及其分岔特性研究

For the design issue of the new generation wide body aircraft landing gears which are complex with statically indeterminate three-dimensional mechanism, bifurcation theory and continuation method are put forward, replacing traditional dynamics perturbation method, to conduct the locking performance study mechanism design. In this project, bifurcation theory is adopted to clarify the jump principle of the moments of locking and unlocking. The laws of retraction performance change of landing gears with single or double brace rods are studied, under the effects of parametric coupling of structure, clearance and joint deformation. The influence factors which lead to the interaction of double brace rods statically indeterminate mechanism are analyzed. The parameter interval which meets the high performance is optimized. By experimenting and studying on a scaled-down prototype, the theoretical results are verified to guide and perfect the analysis procedure. This project study is hopeful to systematically establish a collection of methods of landing gear rapid design and fault analysis based on bifurcation theory. It can be a powerful analysis mean for the early stage of aircraft landing gear research and development. The research results have significant scientific significance and engineering application value for the development of large aircraft landing gear retraction system of our nation.

针对新一代宽体客机起落架超静定三维复杂机构的设计问题，提出应用分岔理论和延拓法来取代传统动力学摄动法开展起落架撑杆锁定性能的研究并指导机构的设计。本项目采用分岔理论阐明收放机构临近上锁瞬间和解锁瞬间突变的机理，研究结构、间隙及关节变形等多参数耦合作用下单、双撑杆式起落架收放机构性能的变化规律，分析致使双撑杆超静定机构相互掣肘的影响因素，优化满足高性能的参数区间，并通过缩比样机性能试验研究，验证理论结果并指导完善分析过程。该项目研究有望系统地建立一套基于分岔理论的起落架机构快速设计与故障分析方法，可成为飞机起落架研发初期强有力的分析手段，其研究成果对我国大型飞机的起落架收放系统的研制具有重要的科学意义和工程应用价值。

针对新一代宽体客机起落架超静定三维复杂机构的设计问题，提出应用分岔理论和延拓法来取代传统动力学摄动法开展起落架撑杆锁定性能的研究并指导机构的设计。.本项目首先针对单撑杆式起落架构型，研究出多参数耦合对锁机构性能的影响规律，形成了一套完整基于分岔理论的收放机构设计方法；基于该方法由单撑杆构型延伸至双撑杆静不定机构的性能研究，构建了双撑杆机构协同上锁的动力学分岔模型，阐明了双锁机构相互掣肘及稳定性问题的根本原因；开展考虑关节间隙对收放机构同步上锁性能影响的研究，并给出满足同步上锁条件的结构参数可行域；最后通过缩比样机性能试验研究，验证理论结果并指导完善分析过程。.本项目首次从机构运动奇异的角度解释起落架机构锁定时的跳跃现象，阐述了造成双撑杆起落架前后撑杆相互掣肘和理想铰接条件下双撑杆起落架机构锁定失效的根本原因；探究出了多参数耦合对双撑杆起落架收放装置同步锁定性能的影响规律；系统地建立了一套基于分岔理论的起落架机构快速设计方法，可作为飞机起落架研发初期强有力的分析手段。其研究成果对我国大型飞机的双撑杆起落架收放系统的研制具有重要的科学意义和工程应用价值。