刚体

Geostatics and hydrokinetics are used to develop equations relating the variation of the mass, centroid and moment of inertia because of the fuel combustion, and the change of the propeller thrust as the AUV cruises. A complete mathematical model is presented for an AUV with variable mass and velocity.

利用刚体分析动力学和理论流体力学的基本理论，研究水下自航器因燃料的消耗而引起的质量变化、质心位置和转动惯量的变化，导出描述其变化规律的方程；研究因推力变化而引起速度的改变，导出推力变化方程。

Hamilton discovered the quaternion ,to the middle period of last century,the application of the quaternion and the quaternion matrix are discovered widely in geostatics,the theory of ped-top using, strap-down inertial ,naviation, enginery and organ,robot technology and artificial satellite attitude control,and so on.

R。 Hamilton发现四元数到上世纪中叶，四元数和四元数矩阵方法在刚体动力学、陀螺使用理论、捷联惯性导航、机器与机构、机器人技术、人造卫星姿态控制等领域应用非常广泛。

The coupling effect between elastic deformation and the rigid motion was concerned in the dynamic equations. At the same time, the flexible manipulators were assumed as Euler-Bernoulli beams, the elastic deformation of the manipulator was represented by modality truncation equations, both elastic and gravitational potential energy were considered to calculate the total energy for whole system, therefore the finial dynamic modeling is more accurate and simple than others published.

该方法考虑了柔性机械臂刚体运动和弹性变形之间的耦合影响，并将柔性机械臂假设为一段Euler-Bernoulli梁处理，将弹性变形用截断模态方程表示，同时考虑了弹性势能和重力势能的影响，得到的双连杆柔性机械臂的动力学模型具有模型准确、结构简单等特点。

Vertical vibration of a rigid body on fluid saturated porous half space is studied.

研究圆柱形刚体在多孔饱和半空间上的垂直振动。

According to the features and analysis of a howitzer ,some components are considered as rigid bodies and some as springs.

根据某火炮的结构特点和分析要求，把一些工程元件简化成刚体，另一些工程元件简化成弹簧，用有限多个质量、转动惯量、弹簧和阻尼形成一个离散的参数系统，从而得到火炮系统的简化模型。

The indenter is assumed rigid and the periodic boundary conditions are set along the X and Y-directions of the model.

分析方法是假设探针为刚体，并将X和Y方向边界设定为周期边界条件。

On the basis of the model, distribution of the first four order natural frequency is analyzed within workspace of the manipulator. Displacement error of moving platform is studied under excitations of external forces and inertial force. Maximum dynamic stress in each time and position of its occurrence are given.

在该模型的基础上，分析了机械手在工作空间的前四阶固有频率的分布情况；研究分析了在外力和刚体惯性力激励下机械手动平台的位置误差；给出了构件在各个时刻的最大动应力及其出现的位置。

Four-node degenerated shell element and rigid shell element are used in our FEM model.Updated Lagrange formulation and rate form constitutive equation are adopted to solve the problem of large strain and large rotation in sheet forming process.Sheet metal material property is described by plastic anisotropy yielding model and isotropic hardening model.Master surface-slave surface contact model is used to define the contact between tools and blank.Contact constraints are enforced with a kinematic algorithm and friction stress is computed by Coulomb friction law.Dynamic relaxation method is used to treat springback after forming stroke.

四结点蜕化壳单元和刚体壳单元分别用来建立板和模具的有限元模型；更新Lagrange法和速率型本构关系被用来处理板料变形中的大应变和大转动；材料模型采用塑性各向异性屈服与等向强化模型；通过主从面模型定义板料和模具的接触，接触算法采用运动约束法，摩擦力用库仓定律计算；并利用动力松弛法对回弹过程进行了计算。

Point to take MQ2535 portal crane jib system as to research object, take finite element and mechanical kinetics as to theoretical fundamental, make use of ansys8.1 to emulate jib systemic at the course of luffing in dynamics , obtain luffing procedural dynamics data of rigid body and elastic body of the jib system , according to those data,which is to improve these system designs beneficial conclusion henceforth.

针对以上问题，本文以MQ2535门座起重机臂架系统为研究对象，以有限元和机械动力学为理论基础，借助ANSYS8.1对臂架系统的变幅过程进行了动力学仿真，得到了臂架系统刚体和弹性体变幅过程的动力学数据，从数据中得到了对今后改善该系统设计的有益结论。

The dynamical equations of a liquid-filled tank were deduced using Jourdain principle,including the momentum and angle momentum equations for the coupling system and Navier-Stokes equations for the liquid sloshing.

液体模块采用Lagrange-Euler描述方法建立有限元计算模型；充液刚体模块利用二阶显式Runge-Kutta格式离散的常微分方程组。

However, as the name（read－only memory）implies, CD disks cannot be written onorchanged in any way.

然而，正如其名字所指出的那样，CD盘不能写，也不能用任何方式改变其内容。

Galvanizes steel pallet is mainly export which suits standard packing of European Union, the North America. galvanizes steel pallet is suitable to heavy rack. Pallet surface can design plate type, corrugated and the gap form, satisfies the different requirements.

镀锌钢托盘多用于出口，替代木托盘，免薰蒸，符合欧盟、北美各国对出口货物包装材料的法令要求；喷涂钢托盘适用于重载上货架之用，托盘表面根据需要制作成平板状、波纹状及间隔形式，满足不同的使用要求。