【作者】 赵欣；

【导师】 陆念力；

【作者基本信息】 哈尔滨工业大学 ， 机械设计及理论， 2013， 博士

【摘要】 本课题来源于国家“十一五”科技支撑计划项目“无脚手架安装作业装备技术研究与产业化开发”中的《大型桥梁检测、维护作业设备技术与产业开发》(2008BAJ09B01-3)的子课题。桥检车全称桥梁检测作业车，是对桥梁进行流动安全检测的专用车辆。桥梁检测车的架设过程和进入桥梁检测状态时的回转制动过程是复杂的大范围柔性运动过程。格构式桥梁检测车的臂架本身为运动的柔性梁杆系统，该系统可视为由固连于运动构件上的随动坐标的刚体运动与弹性构件本身的弹性动态变形组成的刚柔耦合系统。以往的计算分析中，多侧重于桥梁检测过程小位移状态下的微幅运动，将格构式桥梁检测车看成结构，以起制动产生的加速度或惯性力为激励，对其进行微幅振动分析；对桥梁检测车架设过程则通常采用刚体动力学分析，以获得的机构加速度、惯性力施加于约束后的弹性结构上，用动态静力分析代替真正的运动弹性动力分析。这显然与桥梁检测车实际工作状态不符。本文运用多体系统动力学分析方法分别对格构式桥梁检测车的架设过程进行多体刚体系统动力学分析，对其柔性回转制动过程进行计及二阶效应的多柔体系统动力学分析以及考虑刚柔耦合效应的运动柔性系统动力学分析。本课题的目的在于得到一个针对具有弹性构件的格构式桥梁检测车进行多体系统动力学分析行之有效的方法，使之既与格构式桥梁检测车的实际工作模型相符合又便于实际分析应用。论文在多柔体系统动力学分析方法的基础上，以考虑大范围运动梁杆二阶效应的运动弹性动力分析方法，对格构式桥梁检测车进行刚柔耦合动力学分析研究。首先采用等效元素集成法对格构式桥梁检测车的架设过程进行多刚体系统动力学分析，考虑可能出现的多自由度情况，得到相应过程下的臂架系统位移、速度、加速度及油缸力随时间变化的规律及机构运动参数，为桥检车机构设计提供理论依据。而后利用三次样条插值函数构建柔性单元变形场，推导在静力条件下平面和空间的Euler-Bernoulli梁单元几何非线性刚度矩阵，使其在形式上与传统梁单元保持一致；通过对平面和空间结构进行计算分析，验证采用本文方法所获得的新单元计算分析精度远高于传统非线性梁单元，具有很好的适用性。由广义虚位移原理分别建立了柔性多体系统平面动力学方程和空间动力学方程，并对格构式桥梁检测车的竖向伸缩臂端部在制动过程中变形情况进行了计及二阶效应的多柔体系统动力学分析，得到了通常采用多刚体系统动力学分析方法所不能得到的分析结果。本文在格构式桥检车多柔体系统动力学建模中，对由众多梁杆单元构成的格构式构件首先采用等效柔性元素法进行子结构等效，此后在实际结构强度计算分析中对每个杆件单元进行分析计算。在整台桥检车架设和工作过程中，各杆件受力因工况的不同而发生变化，每个杆件最大受力的时刻也在发生变化，为保证结构的安全可靠，对各工况的全过程的计算分析尤为重要。因此需对桥检车的特定工况运用多柔体系统动力学理论，考虑刚体大运动和弹性小变形的耦合项，建立一种由运动格构式结构与柔性机构相互耦合的动力学系统分析方法，尤其在严格的理论分析基础上给出适于工程实用的高效建模与计算求解方法。对于桥检车回转制动过程，由于其为空间结构且杆件众多，本文以CompaqVisual Fortran6.1为平台，编制了有限元计算程序进行了动力学分析，得到了每个杆件随时间变化的变形情况和受力情况。通过与实验样机的检测结果进行比较，验证了本文计算理论与分析方法的有效性。本课题研究，不仅对格构式桥检车这样的具有大范围运动的柔性机械有意义，对类似的运动格构式系统，亦有重要的参考借鉴价值。更多还原

【Abstract】 This subject comes from the sub-topics (2008BAJ09B01-3) named large bridgeinspection and maintenance equipment which is contained in National EleventhFive-Year Technology Support Project ‘Research and industry development onscaffold-less installation equipment’. Bridge inspection truck is a type of specialvehicle to test safety of bridge. The processes of the erecting and slewing brakingare complex large-range flexible motion processes. The jib system of lattice bridgeinspection truck is a mobile flexible beam system, which is a type of rigid-flexiblecoupling system composed of rigid motions of concomitant coordinates fixed withmotive mechanisms and elastic dynamic deformations of elastic mechanisms. In theprevious analysis, attention of slight movement under the state of smalldisplacements in the inspecting condition for bridge is paid. Bridge inspection truckis analyzed with slight movement in the exciting force of acceleration and inertiaforce from starting-braking process. Rigid body dynamics analysis is used in theerecting condition, and the real elastic dynamic analysis is substituted by kinematicstatic analysis by applying contained acceleration and inertia force to constrainedelastic structure. This method does not match the actual working model. For latticebridge inspection truck, this paper applies rigid multi-body dynamic analysis to theerecting process, flexible multi-body dynamic analysis to the flexible slewingbraking process and mobile flexible dynamic analysis considered of rigid-flexiblecoupling effects. The purpose of this project is to find an effective multi-bodydynamic analysis method for lattice bridge inspection truck consisting of elasticcomponents, which is both consistent with the actual working model and convenientfor the practical analysis and calculation.This paper implements the rigid-flexible coupling dynamics analysis to latticebridge inspection truck based on the flexible multi-body system dynamics analysismethods, which considering the movement elastic dynamic analysis method onlarge-scale movement beams with the second-order effect.First, equivalent element integration method is used for rigid multi-bodydynamics analysis in the erecting condition. Considering multiple degrees offreedom, displacement, velocity and acceleration of the jib system, motion parameters of mechanism and variation of the cylinder force are obtained, whichprovide a theoretical basis for the design for lattice bridge inspection truck.Then, the deformation field of flexible element is built using cubic splineinterpolation function. The geometric nonlinear stiffness matrix of the planar andspactial Euler-Bernoulli beam element is derived in the static conditions which isconsistent with the traditional beam element in the form. Through the analysis ofplanar and spatial structure, the results show that the calculation precision of newelement from this method is much higher than traditional beam element, and themethod has a good applicability.Flexible multi-body system dynamics equations of planar and spatial motionwere established by the general principle of virtual displacement. Flexiblemulti-body system dynamics analysis with second-order effect is implemented toobtain the deformation of the end of vertical telescopic boom in the braking processwhich cannot be derived from rigid multi-body dynamics analysis method.In the aforementioned flexible system dynamics modeling of the lattice bridgeinspection truck, equivalent flexible element method is used for substructures of thelattice component, then every beam element is analyzed in strength calculationanalysis of actual structure. In the process of erecting and working of the entirebridge inspection truck, force of every beam changes due to different workingconditions, and the moment of max force is also changing. For ensuring the safetyand reliability, calculation analysis is extremely important to the whole process ofthe various conditions. Therefore, dynamics of flexible multi-body system is usedfor specific conditions of bridge inspection truck. Considering coupling terms aboutlarge motion of rigid body and elastic small deformation, an analysis method ofdynamic system is built coupling motion lattice structure and flexible mechanisms.A method of high efficient modeling and calculating solution which is suitable forengineering applications is implemented on the base of accurate theoretical analysis.For the slewing braking condition, because of its spatial structure and large quantity,finite element program for dynamic analysis based on Compaq Visual Fortran6.1iscompiled. The changing on deformation and forces of each bar with time is obtained.The effectiveness of calculating theory and analysis method from this paper isverified by compared with the test result of experimental prototype. This is not onlymeaningful for flexible mechanism with large range motion like lattice bridge inspection truck, but also large reference value for similar movement lattice system.更多还原