材料课件第二章剪切.pptxVIP

Mechanics of MaterialsCHAPTER 2 SHEAR 材料力学第二章 剪切CHAPTER 2 SHEAR§2－1 STRENGTH CALCULATION ABOUT SHEAR AND BEARING OF CONNECTING MEMBERSEXCERCISE LESSONS OF SHEAR AND BEARING第二章剪 切§2－1 连接件的剪切与挤压强度计算拉压和剪切习题课SHEARProduction of the shearing stress剪切剪应力的产生PPSHEAR§2－1 STRENGTH CALCULATION ABOUT SHEAR AND BEARING OF CONNECTING MEMBERS1、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 member is small，but it plays the role of passing loads. boltCharacteristic：It can pass general loads and can be dismounted. PP剪切§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， 可拆卸。PPGearmmKeyShaftSHEARno gaprivetCharacteristic: It can pass general loads, but can not be dismounted.for example, the truss in a bridge is connected by it.Characteristic: It can pass torques.PP齿轮m键m轴特点：传递扭矩。剪切无间隙铆钉特点：可传递一般 力，不可拆卸。如桥梁桁架结点处用它连接。nn（Resultant）PP（Resultant）SHEAR2)Characteristics of loads and deformation：Use a rivet as an example：① Characteristic of loads： The rivet is subjected to two equal and opposite forces. The acting lines of these two forces are very close. ② Characteristic of deformation: Two parts subjected to two equal and opposite forces tend to shift over one another along the junction plane of two forces.（合力）nnP（合力）P剪切2、受力特点和变形特点：以铆钉为例：①受力特点： 构件受两组大小相等、方向相反、作用线相距很近（差一个几何平面）的平行力系作用。②变形特点： 构件沿两组平行力系的交界面发生相对错动。PPnnShearing planeQnnPSHEAR③Shearing plane： The plane along which two parts of the member tend to shift over one another. Such as n– n .（Resultant（ Resultant ）④Internal force on shearing plane： Internal force — Shearing force Q ，its acting line is parallel to the shearing plane.（合力）nnP（合力）P剪切面QnnP剪切③剪切面： 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 ，其作用线与剪切面平行。(Resultant ）nnP(Resultant )PShearing planeQnnPSHEAR3)Three kinds of breakage at joint： ①Failure due