英汉双语材料力学2PPT课件

P
as n– n .
（ Resultant ）④Internal force on shearing plane：
Shearing plane
n P
Internal force — Shearing force Q ，its acting line is parallel to the shearing plane.
n
构件受两组大小相等、方向相 反、作用线相距很近（差一个几 n 何平面）的平行力系作用。
P （合力） ②变形特点：
构件沿两组平行力系的交界面
发生相对错动。
（Resultant P
n
Q n
③Shearing plane：
The plane along which two parts of the
n
member tend to shift over one another. Such
n
n
③Breakage due to tension
P
The steel plate is weakened in the section in
which the rivet holes exist and stress in the
weakened section increases so that the steel plate is easily broken due to
Use a rivet as an example： ① Characteristic of loads：
（Resultant） P
n
The rivet is subjected to two equal and opposite forces. The acting lines of these
n two forces are very close. P （Resultant）② Characteristic of deformation:
member is small，but it plays the role of passing loads.
bolt
Characteristic：It can
P
P
pass general loads and can be
dismounted.
§2－1 连接件的剪切与挤压强度计算
一、连接件的受力特点和变形特点：
1、连接件
在构件连接处起连接作用的部件，称为连接件。例如： 螺栓、铆钉、键等。连接件虽小，却起着传递载荷的作用。
螺栓
特点：可传递一般 力，
P
P
可拆卸。
P P
no gap rivet Characteristic: It can pass general loads, but can not be dismounted.for example,
Two parts subjected to two equal and opposite forces tend to shift over one another along the junction plane of two forces.
2、受力特点和变形特点：
以铆钉为例：
①受力特点：
（合力） P
such as along section n– n. ②Breakage due to bearing
Fail due to mutual bearing between the
Shearing
Q
plane rivet and the steel plate in their connecting plane.
tension at the connecting position.
（合力） P
n
Q n
3、连接处破坏的三种形式：
①剪切破坏
n
沿铆钉的剪切面剪断，如
P （合力）
沿n– n面剪断 。 ②挤压破坏
剪切面
n P
铆钉与钢板在相互接触面 上因挤压而使溃压连接松动， 发生破坏。
③拉伸破坏
钢板在受铆钉孔削弱的截面处，应力增大，易在连接处拉断。
2、Practical calculation of shear
Mechanics of Materials
CHAPTER 2 SHEAR
§2－1 STRENGTH CALCULATION ABOUT SHEAR AND BEARING OF CONNECTING MEMBERS
EXCERCISE LESSONS OF SHEAR AND BEARING
第二章 剪 切
the truss in a bridge is connected by it.
Gear m
Key m
Shaft Characteristic: It can pass torques.
P P
铆钉
无间隙
特点：可传递一般 力，不可拆卸。如桥梁桁架结点处用它连接。
齿轮
m 键
m
轴 特点：传递扭矩。
2)Characteristics of loads and deformation：
§2－1 连接件的剪切与挤压强度计算
Production of the shearing stress
剪应力的产生
§2－1 STRENGTH CALCULATION ABOUT SHEAR AND BEARING OF CONNECTING MEMBERS
1、Characteristics of loads and deformation of connecting members:
1)Connecting member
The structure member that connects one member to another is called the
connecting member. Such as：bolts、rivets、keys etc. The connecting
（合力） P
n
Q n
③剪切面：
n
P （合力）
构件将发生相互的错动面，如 n– n 。
④剪切面上的内力：
内力 — 剪力Q ，其作用线与 剪切面 剪切面平行。
n P
(Resultant ） P
n
3)Three kinds of breakage at joint：
n
P (Resultant )
①Failure due to shear Snip along the shearing plane of