刚体力学英语怎么说及英文单词

发布时间: 2021-02-22 19:05:45

⑴ 物理刚体力学

m下滑到来底，自机械能守恒：v=√(2gh) ，(1)

m与M碰撞，角动量守恒：m.v.L=J.ω， (2) ，其中，J=(M.L^2/3+m.L^2)ω，

碰撞后系统机械能守恒：J.ω^/2=MgL(1-cosθ)+Mg(L/2)(1-cosθ) ，(3)

由以上3个式可解得θ 。

⑵ 刚体力学。。

动量矩守恒：m.v0(L/2)=J.ω
ω=m.v0(L/2)/J=m.v0(L/2)/(mL^2/12+m(L/2)^2)=3v0/(2L)

⑶ 求有关刚体力学的英文文献急！

刚体力学 rigid body mechanics

这里有啊
http://www.multires.caltech.e/teaching/courses/cs101.3.spring02/cs101_files/notes/RigidBodyMechanics.pdf

In physics, a rigid body is an idealization of a solid body of finite size in which deformation is neglected. In other words, the distance between any two given points of a rigid body remains constant in time regardless of external forces exerted on it. In classical mechanics a rigid body is usually considered as a continuous mass distribution, while in quantum mechanics a rigid body is usually thought of as a collection of point masses. For instance, in quantum mechanics molecules (consisting of the point masses: electrons and nuclei) are often seen as rigid bodies (see classification of molecules as rigid rotors).

Kinematics

[edit] Position
The position of a rigid body can be described by a combination of a translation and a rotation from a given reference position. For this purpose a reference frame is chosen that is rigidly connected to the body (see also below). This is typically referred to as a "local" reference frame (L). The position of its origin and the orientation of its axes with respect to a given "global" or "world" reference frame (G) represent the position of the body. The position of G not necessarily coincides with the initial position of L.

Thus, the position of a rigid body has two components: linear and angular, respectively. Each can be represented by a vector. The angular position is also called orientation. There are several methods to describe numerically the orientation of a rigid body (see orientation). In general, if the rigid body moves, both its linear and angular position vary with time. In the kinematic sense, these changes are referred to as translation and rotation, respectively.

All the points of the body change their position ring a rotation about a fixed axis, except for those lying on the rotation axis. If the rigid body has any rotational symmetry, not all orientations are distinguishable, except by observing how the orientation evolves in time from a known starting orientation.

In two dimensions the situation is similar. In one dimension a "rigid body" can not move (continuously change) from one orientation to the other.

[edit] Other quantities
If C is the origin of the local reference frame L,

the (linear or translational) velocity of a rigid body is defined as the velocity of C;
the (linear or translational) acceleration of a rigid body is defined as the acceleration of C (sometimes referred at material acceleration);
the angular (or rotational) velocity of a rigid body is defined as the time derivative of its angular position (see angular velocity of a rigid body);
the angular (or rotational) acceleration of a rigid body is defined as the time derivative of its angular velocity (see angular acceleration of a rigid body);
the spatial or twist acceleration of a rigid body is defined as the spatial acceleration of C (as opposed to material acceleration above);
For any point/particle of a moving rigid body we have

where

represents the position of the point/particle with respect to the reference point of the body in terms of the local frame L (the rigidity of the body means that this does not depend on time)
represents the position of the point/particle at time
represents the position of the reference point of the body (the origin of local frame L) at time
is the orientation matrix, an orthogonal matrix with determinant 1, representing the orientation (angular position) of the local frame L, with respect to the arbitrary reference orientation of frame G. Think of this matrix as three orthogonal unit vectors, one in each column, which define the orientation of the axes of frame L with respect to G.
represents the angular velocity of the rigid body
represents the total velocity of the point/particle
represents the translational velocity (i.e. the velocity of the origin of frame L)
represents the total acceleration of the point/particle
represents the translational acceleration (i.e. the acceleration of the origin of frame L)
represents the angular acceleration of the rigid body
represents the spatial acceleration of the point/particle
represents the spatial acceleration of the rigid body (i.e. the spatial acceleration of the origin of frame L)
In 2D the angular velocity is a scalar, and matrix A(t) simply represents a rotation in the xy-plane by an angle which is the integral of the angular velocity over time.

Vehicles, walking people, etc. usually rotate according to changes in the direction of the velocity: they move forward with respect to their own orientation. Then, if the body follows a closed orbit in a plane, the angular velocity integrated over a time interval in which the orbit is completed once, is an integer times 360°. This integer is the winding number with respect to the origin of the velocity. Compare the amount of rotation associated with the vertices of a polygon.

[edit] Kinetics
Main article: Rigid body dynamics
Any point that is rigidly connected to the body can be used as reference point (origin of frame L) to describe the linear motion of the body (the linear position, velocity and acceleration vectors depend on the choice).

However, depending on the application, a convenient choice may be:

the center of mass of the whole system;
a point such that the translational motion is zero or simplified, e.g on an axle or hinge, at the center of a ball-and-socket joint, etc.
When the center of mass is used as reference point:

The (linear) momentum is independent of the rotational motion. At any time it is equal to the total mass of the rigid body times the translational velocity.
The angular momentum with respect to the center of mass is the same as without translation: at any time it is equal to the inertia tensor times the angular velocity. When the angular velocity is expressed with respect to the principal axes frame of the body, each component of the angular momentum is a proct of a moment of inertia (a principal value of the inertia tensor) times the corresponding component of the angular velocity; the torque is the inertia tensor times the angular acceleration.
Possible motions in the absence of external forces are translation with constant velocity, steady rotation about a fixed principal axis, and also torque-free precession.
The net external force on the rigid body is always equal to the total mass times the translational acceleration (i.e., Newton's second law holds for the translational motion, even when the net external torque is nonnull, and/or the body rotates).
The total kinetic energy is simply the sum of translational and rotational energy.

[edit] Geometry
Two rigid bodies are said to be different (not copies) if there is no proper rotation from one to the other. A rigid body is called chiral if its mirror image is different in that sense, i.e., if it has either no symmetry or its symmetry group contains only proper rotations. In the opposite case an object is called achiral: the mirror image is a , not a different object. Such an object may have a symmetry plane, but not necessarily: there may also be a plane of reflection with respect to which the image of the object is a rotated version. The latter applies for S2n, of which the case n = 1 is inversion symmetry.

For a (rigid) rectangular transparent sheet, inversion symmetry corresponds to having on one side an image without rotational symmetry and on the other side an image such that what shines through is the image at the top side, upside down. We can distinguish two cases:

the sheet surface with the image is not symmetric - in this case the two sides are different, but the mirror image of the object is the same, after a rotation by 180° about the axis perpendicular to the mirror plane.
the sheet surface with the image has a symmetry axis - in this case the two sides are the same, and the mirror image of the object is also the same, again after a rotation by 180° about the axis perpendicular to the mirror plane.
A sheet with a through and through image is achiral. We can distinguish again two cases:

the sheet surface with the image has no symmetry axis - the two sides are different
the sheet surface with the image has a symmetry axis - the two sides are the same

[edit] Configuration space
The configuration space of a rigid body with one point fixed (i.e., a body with zero translational motion) is given by the underlying manifold of the rotation group SO(3). The configuration space of a nonfixed (with non-zero translational motion) rigid body is E+(3), the subgroup of direct isometries of the Euclidean group in three dimensions (combinations of translations and rotations).

⑷ 帮忙翻译力学专业英语

6．(1)Equate to zero the moment about one point and the force sums in two directions. This is the approach of Eqs.(2a,b).
对某点的力矩的和，和在俩个方向上力的和等于零
(2) )Equate to zero the moment sums about two points and the force sum in a direction that is not perpendicular to the line connecting the two chosen points.
对两点的力矩的和，和在一个方向上力的和等于零，这个方向与所选的两点的连接不垂直
(3)Equate to zero the moment sums about three points that are not collinear.
对不共线的三点的力矩的和等于零
7．(1)A particle will remain at rest or move with constant speed along a straight line, unless it is acted upon by a resultant force.
一个质点，在没有受到合外力作用时，总保持静止或匀速直线运动状态
(2)When a resultant force is exerted on a particle, the acceleration of that particle is parallel to the direction of the force and the magnitude of the acceleration is proportional to the magnitude of the force.
当一个质点受到合外力作用时，质点加速度的方向与合外力的方向相平行，而且加速度的大小与力的大小成正比
(3)The force exerted on one particle by another is equal and opposite to the force exerted by the first particle on the second.
一个质点对另一个质点的作用力与第二个质点对第一个质点的作用力大小相等，方向相反
8.The motion of a rigid body consists of a superposition of two movements.The first part consists of a movement of all points following the motion of an arbitrarily selected point in the body. The second movement is a rotation about the selected point in which all lines rotate by the same amount.
一个刚体的运动有两个重叠的运动组成。第一部分包括一个所有点都跟随刚体上任意基点的平动的运动。第二部分的运动是关于几点的转动，在转动中过基点所有的线以相同的角速度转动
15.As mentioned previously, the dynamic effect,I.e.,the influence of inertia forces on the process of stress development in a body, depends on the dynamic loading conditions. These are quasi-static states of stress, vibrations, and stress waves. The limits between these groups are not clearly defined, however, and frequently the phenomena associated with more than one group can occur in the same dynamic event .
如前所述，动态力的影响，即惯性力是一个物体的应力变化过程的影响，取决于动态负载的情况，可分为三种典型现象。他们分别是（1）准静态应力状态（2）振动和（3）应力波动。这三组的界限，不是清楚地被定义的。然而，经常地联系不止一个组的现象，能发生在同一个动力学的问题中

⑸ 大学物理刚体力学问题

由机械能守恒你以求出
碰撞前杆角百速度ω度
。
由动量矩守恒
：
J.ω=J.ω'+v.m.L
(1)
,
ω'--碰撞后问杆角速度
，v--碰撞后物块速度
完全弹性碰撞，碰撞前后动能答不变
：
J.ω^2/2=J.ω'^2/2+mv^2/2
(2)
(1)
(2)联立可解得
ω'
和
v
取物块m
：a=-μ专mg/m=-μg
,
匀加速v-s公式
0-v^2=2a.s
-->物块滑过属的距离
s=-v^2/(2a)=v^2/(2μg)

⑹ 刚体力学是什么〉〉

是与流体力学相对应的一个物理力学门类。

⑺ 刚体力英文怎么说

刚体力学:

1. geostatics
刚体力应该是rigid body

其它相关解释:
<mechanics of rigid bodies> <mechanics of rigid body>

⑻ 1——20的英文翻译

1-20的英文翻译及读音如下：

1.one [wQn]

2. two [tu:]

3. three [Wri:]

4. four [fC:]

5. five [faiv]

6. six [siks]

7. seven ['sevEn]

8. eight[eIt]

9. nine [nain]

10.ten [ten]

11.eleven [i'levEn]

12.twelve [twelv]

13.thirteen ['WE:'ti:n]

14.fourteen ['fC:'ti:n]

15.fifteen ['fif'ti:n]

16.sixteen ['siks'ti:n]

17 .seveteen ['sevEn'ti:n]

18 .eighteen ['eI'ti:n]

19.nineteen ['nain'ti:n]

20.twenty ['twenti]

(8)刚体力学英语怎么说及英文单词扩展阅读

一、one释义

cardinal number：一；一个

pron：那个人；那个东西；那种人；一个人；任何人

复数：ones

例句：

1.Beginning at Act one, Scene one.

从第一幕第一场开始。

2.One unit is equivalent to one glass of wine.

一个单位等于一杯酒。

刚体力学英语怎么说及英文单词

与刚体力学英语怎么说及英文单词相关的资讯