超弹性铰链的力学建模及实验研究

发布时间：2018-03-04 13:08

本文选题：三棱柱伸展臂　切入点：超弹性铰链　出处：《哈尔滨工业大学》2015年博士论文　论文类型：学位论文

【摘要】：可展开机构已经广泛应用于宇航空间任务中。近年来,宇航空间任务的复杂化和大规模化的发展趋势,致使可展开机构朝着更轻质量和更低功耗的方向发展。超弹性铰链集驱动、回转、锁定功能于一体,用它来替代传统机械式铰链,应用于可展开机构中不仅具有无摩擦、不需附加驱动装置的特点,还能有效降低其质量和功耗。同时,超弹性铰链是一种空间曲面的薄壳结构,它的大挠度折展过程具有高度非线性的特点。一些尚未被解决的共性问题,例如准确描述其折展过程的弹性应变能建模方法,综合计及大挠度折展、非线性屈曲、大角度过冲现象的多目标优化技术等,仍然制约着超弹性铰链的宇航空间应用。本文首先基于凯拉迪恩(Calladine)壳体理论和冯卡门(von Karman)薄板大挠度理论,同时考虑了横向弯曲、纵向弯曲和纵向拉伸的影响,建立了单带簧超弹性铰链纯弯曲载荷作用时弹性应变能数学模型。基于最小势能原理,利用数值法求解出单带簧超弹性铰链正向和反向纯弯曲过程中的峰值力矩和稳态力矩。设计和搭建实验平台,对12种不同规格单带簧超弹性铰链分别进行准静态正向和反向弯曲实验,验证所建立理论模型的准确性,为后续研究不同组合形式超弹性铰链大挠度变形时力矩特性和三棱柱伸展臂的设计奠定基础。针对不同组合形式超弹性铰链展开状态的稳定性的问题,分别基于欧拉梁屈曲理论和铁木辛柯理论,建立对向和背向多层超弹性铰链的折叠峰值力矩模型。搭建实验平台,对12种不同规格对向和背向的单层、双层超弹性铰链分别进行实验,验证所建立折叠屈曲力矩理论模型的正确性。鉴于超弹性铰链折展时存在应力集中影响使用次数,以及驱动能力是否满足需求的问题,基于多项式响应面法,建立整体式双缝超弹性铰链准静态展开的最大应力、展开峰值力矩和稳态力矩的数学代理模型,对缝体几何参数影响进行研究,利用改进的非支配遗传算法进行优化得到最优参数。建立对向双层超弹性铰链准静态展开力学特性参数的数学模型,进行准静态力学特性多目标优化设计得到铰链最优的横截面几何尺寸,并研究横截面几何参数的影响。针对超弹性铰链展开冲击现象,搭建实验平台进行展开动力学实验,对动力学展开的有限元模型进行修正。在准静态折展优化的基础上,以过冲角度最小和完全锁定时间最短为目标,以最大应力为约束,设置位于弯曲外侧的内层和外层带簧厚度为自变量,利用修正了的有限元模型进行动力学展开特性优化。研究结果对解决三棱柱伸展臂低冲击和快速锁定等设计问题具有重要意义。设计一种10单元含对向双层超弹性铰链的三棱柱伸展臂结构,通过静力学分析建立其展开状态弯曲刚度和压缩刚度模型。利用有限元仿真法对10单元含对向超弹性铰链的三棱柱伸展臂进行展开基频和模态预测,并进行参数灵敏度分析。研制出2单元含对向双层超弹性铰链的三棱柱伸展臂,采用弹性绳吊挂和球轴承支撑补偿重力的方法,对2单元三棱柱伸展臂的展开重复性进行了实验。采用锤击法测量了2单元三棱柱伸展臂悬挂和悬臂状态的基频和模态,利用10单元三棱柱伸展臂模态分析的有限元建模方法对2单元伸展臂悬臂状态进行模态分析,前五阶振型完全一致,前五阶基频的仿真值与实验值误差不大于5.501%,从而验证了10单元三棱柱伸展臂仿真的准确性,为含超弹性铰链的三棱柱伸展臂方案设计提供分析依据。
[Abstract]:Deployable mechanism has been widely used in space missions. In recent years, complicated and large-scale development trend of space missions, which can be the opening mechanism towards light quality and lower power consumption direction. The super elastic hinge in rotary drive, locking functions, use it to replace the traditional mechanical hinge mechanism not only has no friction applied to spread, does not need additional driving device characteristics, can effectively reduce the quality and power consumption. At the same time, the super elastic hinge is a shell structure of space surface, characteristics of large deflection of its unfolding process is highly nonlinear. Some common problems have not been solved for example, an accurate description of the unfolding process of elastic strain energy modeling method, comprehensive and large deflection unfolding, nonlinear buckling, large angle overshoot of multi-objective optimization technique, still about super elastic hinge Space application chain. Based on the Kara Dean (Calladine) and Pangkamen (von Karman shell theory) theory of large deflection of thin plate, considering the effects of transverse bending, longitudinal bending and longitudinal tension, a single band spring super elastic hinge pure bending with elastic strain energy mathematical model based on the principle of minimum energy. By using the numerical method, the peak torque and the steady-state torque of a single band spring super elastic hinge forward and reverse bending process. The design and build the experiment platform, 12 kinds of different specifications of the single band spring super elastic hinge were quasi static forward and reverse bending experiments, verifying the accuracy of the model, to lay the foundation for design of deformation follow-up study different combinations of super elastic hinge torque and large deflection when the triangular prism mast. According to different combinations of super elastic hinge unfolded state The question of stability, based on Euler buckling theory and Timoshenko beam theory respectively, and to establish the back folding model to the peak torque of multilayer super elastic hinge. The experimental platform is built, on 12 different specifications of and at the back of the monolayer, double super elastic hinge test were carried out to verify the correctness of folding and buckling the moment theory model. In view of the super elastic hinge unfolding when there is stress concentration effect of the frequency of use, and whether the ability to meet the needs of the driver, the polynomial response surface method based on a monolithic double slit maximum stress super elastic hinge quasi-static expansion, the mathematical model the peak torque and steady-state torque, research the geometric parameters on the body, the non dominant genetic algorithm to get the optimal parameter optimization. The establishment of the double super elastic hinge to quasi static mechanical properties of expansion parameter number Model of multi objective optimization design cross sectional geometry hinge optimal quasi static mechanical properties, and to study the influence of geometric parameters on the cross section. The impact phenomenon of the super elastic hinge, build the experimental platform of dynamic experiment, finite element model of dynamics was modified. Based on quasi-static unfolding optimization on the overshoot and the minimum angle locked in the shortest time, the maximum stress as constraint, with spring thickness of inner and outer variables set in lateral bending, dynamic expansion characteristic optimization using the finite element model was modified. The research results have important significance to solve design problems of three prism stretch low arm the impact and fast locking. The design of a 10 unit with stretching arm structure on the three prism to double super elastic hinge, through the static analysis to establish the unfolded state The bending rigidity and compressive stiffness model. Using the finite element simulation method of unit 10 to three super prism containing elastic hinge arms of the fundamental frequency and modal prediction, and parameter sensitivity analysis is developed. The 2 unit containing of three prism to double super elastic hinge arms, support with gravity compensation method elastic rope hanging and ball bearing, on the 2 unit three prism stretching arm expansion repetitive experiments were carried out. By using hammering method measuring 2 prism unit three stretching arm suspension and cantilever frequency and modal, using 10 unit three prism extended finite element modeling method of arm modal analysis of 2 unit mast cantilever modal analysis, the first five modes is completely consistent, the simulation value of the fundamental frequency of the first five order error is less than 5.501% with the experimental data, which verified the accuracy of the 10 unit three prism stretching arm simulation, with super elastic hinge The three prism extension arm design provides the basis for analysis.

【学位授予单位】：哈尔滨工业大学
【学位级别】：博士
【学位授予年份】：2015
【分类号】：V414

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