【作者】 李媛媛；

【导师】 黄文虎； 王聪；

【作者基本信息】 哈尔滨工业大学 ， 一般力学与力学基础， 2019， 博士

【摘要】 航天器附件大尺度、大挠性的发展趋势对在轨空间结构的展开、刚柔耦合控制提出新的要求;而高精度、高分辨率的观测需求为航天器在轨运行时的微振动、热致振动等研究带来了新的课题。普遍存在的铰链间隙会引发系统复杂的非线性力学行为,给运行环境恶劣且呈现出多耦合、非线性特性的空间可展开结构的研究带来了新的挑战。太阳翼作为航天领域几乎必不可少的空间可展机构,呈现出典型的刚柔耦合特性。太阳翼系统能否在入轨后顺利地展开并迅速地达到平衡状态,并且正常、稳定、可靠地在轨运行,直接关系到航天任务的成败。本文建立了含间隙铰机构的刚柔耦合动力学模型并将其应用于可展开太阳翼的动力学分析中,研究了含间隙的太阳翼系统在展开阶段的动力学特性和在轨运行阶段的热致振动特性。主要研究内容和成果如下:建立了考虑铰链间隙及磨损的机构刚柔耦合多体动力学模型。分别采用自然坐标法(NCF)和绝对节点坐标法(ANCF)描述系统中刚体和柔体的运动;选取两状态模型描述间隙铰链,分别采用非线性Lankarani-Nikravesh接触力模型和改进的Coulomb摩擦模型描述间隙处的法向接触力和切向摩擦力;采用Archard磨损模型描述间隙磨损。利用广义?方法对含铰链间隙的多体动力学方程进行求解,并且验证了所建立模型的有效性。基于ADAMS软件建立了考虑铰链间隙的刚性太阳翼动力学模型。着重分析了扭簧机构、绳索联动机构和锁定机构的关键参数对含间隙太阳翼系统展开稳定性及可靠性的影响。得出了机构参数的选取依据:在满足各机构基本功能的参数范围内,扭簧机构采用较小的等效刚度系数和较大的预载荷、绳索联动机构采用较小的等效刚度系数以及锁定机构采用较小的等效刚度系数,更有助于提高系统锁定后的稳定性和连接机构的可靠性。针对展开阶段的太阳翼系统,对考虑铰链间隙和翼板柔性的平面刚柔耦合可展开太阳翼系统进行动力学分析。并采用ADAMS和有限元软件联合仿真验证基于NCF-ANCF方法所建的太阳翼刚柔耦合动力学模型的有效性。对含间隙铰可展开太阳翼模型的航天器姿态进行分析,结果表明铰链间隙对柔性太阳翼系统的影响比刚性系统要大。研究铰链间隙的数量、大小和间隙铰材料特性对航天器姿态的影响,并设计了航天器姿态控制器。揭示了太阳翼系统展开过程中间隙铰链销轴的运动行为及铰链间隙和太阳翼柔性二者耦合对太阳翼系统动力学特性的作用机理:在初始阶段和锁定后阶段销轴呈现碰撞特性,间隙铰连接太阳翼系统的弹性振动特性起主导作用会加剧太阳翼系统的振动;在展开阶段销轴呈现接触特性,系统的悬浮阻尼特性起主要作用会抑制太阳翼系统的振动。针对在轨运行阶段的太阳翼系统,基于ANCF建立了复合太阳翼的热-结构动力学方程,对受日出热载荷的间隙铰连接柔性太阳翼系统进行刚-柔-热耦合动力学分析。对比研究了太阳翼系统采用铰链连接形式与以往研究中常采用固定连接形式时系统热致振动特性的差异。研究了受日出热载荷或机动力载荷或热-力载荷共同作用的铰连接柔性太阳翼系统的航天器姿态和翼板动响应。发现考虑铰链间隙时,受热-力载荷共同作用的太阳翼系统的振动幅度和振动持续时间远高于单独考虑某种载荷作用时的情况。对运动中的航天器系统而言,太阳辐射热对铰链磨损的影响不容忽视。更多还原

【Abstract】 New requirements are put forward for the dynamics and control of deployable rigidflexible coupling on-orbit spacecraft structures due to the development trend of large scale and large flexible spacecraft accessories;New issues are brought forward for the study and analysis of micro-vibration and thermally induced vibration of on-orbit spacecraft structures due to the growing observation demand of high precision and resolution.Ubiquitous joint clearance can cause complex nonlinear mechanical behaviors to the multi-body system.Considering the effect of joint clearance on spacecraft brings an urgent new challenge to the research of space deployable structures with multicoupling and nonlinear characteristics operating in severe conditions.Solar array system,as an almost indispensable space deployable mechanism in the aerospace field,presents typical rigid-flexible coupling characteristics.Whether it can deploy smoothly,reach equilibrium quickly,and operate normally,stably and reliably in orbit,that directly determines the success or failure of space missions.This thesis establishes the rigid-flexible coupling multibody dynamic model considering joint clearance and applies it into deployable solar array system.The dynamic response in deployment process and thermally induced vibration performance in operation process of solar array system with multiple clearance joints are studied.The main contents and achievements derived in this dissertation are listed as follows.The rigid-flexible coupling dynamical model of multibody system is established considering clearance and wear at joints.Thereinto,the rigid body described by Nodal Coordinate Formulation(NCF)and the flexible body described by Absolute Nodal Coordinate Formulation(ANCF).Two-state model is selected to describe the clearance joint.The normal contact force effect and tangential friction effect at clearance joint are considered by using nonlinear contact force model and amendatory Coulomb friction model,respectively.The wear model is established using Archard’s wear model.Generalized-? method is used to solve system equations of motion.Besides,the availability of the proposed model is verified.The rigid solar array system with multiple clearance joints is established under ADAMS software.Parametric studies indicate some rules to design the key parameters of torque spring,CCL mechanism and latch mechanism: on the basis of meeting the basic functional requirements,the torque spring with the larger preload and smaller stiffness,the CCL mechanism with smaller equivalent stiffness and the latch mechanism with the original damping coefficient and the lesser stiffness coefficient may improve the dynamic response of the solar array system in post-lock phase.For the deployment process of the solar array system,the rigid-flexible coupling deployable solar array system considering panel flexibility and joint clearance is modeled based on NCF-ANCF.The availability of the proposed model is verified through comparing with numerical co-simulations of Patran and ADAMS software.Effects of clearance joints on satellite attitude of the solar arrys model considering panel flexibility is bigger than the stiff system model.Besides,the effects of clearance number,clearance size and clearance stiffness on satellite attitude are investigated.And an attitude controller of spacecraft is designed.Furthermore,action of clearance joints is studied to indicate motion property of journal,which reveals the function mechanism of couplping effects of joint clearance and panel flexibility on dynamics of solar array system: coupled with clearance at collision phase,elastic vibration property of flexible panels dominates to cause system shock at initial phase and post-lock phase;while coupled with clearance at contact phase,suspension damping property of flexible panels dominates to steady the system at deployment phase.For the on-orbit operation process of the solar array system,considering solar radiation,a thermal-structural coupling model of planar solar array system with clearance joint is modeled based on NCF-ANCF.Effects of thermal load and adjustment motion on spacecraft attitude,solar panel dynamics and wear prediction of the system with or without clearance joint are investigated.The degree and duration of the shake of the system with clearance joint increase dramatically,and far beyond the superposition of each single condition.The effect of joint connection type on the thermal induced vibration of solar array system is discussed comparing with fixed connection type adopted in the previous studies.Thermal environment effect on wear prediction is significant and nonignorable for the on-orbit spacecraft.更多还原