文档介绍：Chapter 7: Basic
Theoretical mechanics
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第七章刚体的基本运动
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§7–1 Translational motion of a rigid body
§7–2 Rotation of a rigid body about a fixed axis
§7–3 Velocity and acceleration of a point in a rigid
body rotating about a fixed axis
§7–4 Transmission between two rotating rigid bodies
§7–5 Vector representation of angular velocity and
angular acceleration
Lesson for problem solving
Chapter 7: Basic motions of a rigid body
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§7–1 刚体的平行移动
§7–2 刚体的定轴转动
§7–3 定轴转动刚体内各点的速度与加速度
§7–4 绕定轴转动刚体的传动问题
§7–5 角速度与角速度的矢量表示
点的速度与加速度的矢积表示
习题课
第七章刚体的基本运动
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Chapter 7: Basic motions of a rigid body
The shape and dimensions of a rigid body should be considered investigating its motion. However,due to its unchanged shape,.
§7-1 Translational motion of a rigid body
[Examples]
translation and rotation
Basic motions
Rectilinear translation
curvilinear translation
Rotation about a fixed axis
Kinematics
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第七章刚体的基本运动
[例]
由于研究对象是刚体,所以运动中要考虑其本身形状和尺寸大小,又由于刚体是几何形状不变体,所以研究它在空间的
运动学
是指刚体的平行
移动和转动
§7-1刚体的平行移动(平动)
基本运动
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OB rotates about a fixed axis
The motion of CD is a translation
The motions of AB and of the cam are translations
It is not necessary to determine its position by finding the positions of all its points. Instead, its position is pletely by describing the position of a line or a plane in it.
Kinematics
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OB作定轴转动
CD作平动
AB、凸轮均作平动
运动学
位置就不必一个点一个点地确定,只要根据刚体的各种运动形式,确定刚体内某一个有代表性的直线或平面的位置即可。
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1. Definition of translatory motion of a rigid body:
The direction of the line linking arbitrary two points in the rigid body never changes during its motion.
Note the equations of motion of the points A and B, . and ,we have
The length and direction of AB do not change at all during its motion.
Its trajectory may be
a straight line
a curve
[Example]
Kinematics
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运动学
:
刚体在运动中,其上任意两点的连线始终保持方向不变。
由A,B 两点的运动方程式: 而
[例]
AB在运动中方向和大小始终不变
它的轨迹
可以是直线
可以是曲线
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