searingandbearing.pptVIP

Example7 :Low-carbon structural steel has a shearing ultimate strength of approximately 310MPa. Determine the force P necessary to punch a25mm diameter hole through a plate of this steel 10mm thick. If the modulus of elasticity in shear for this material is 82GPa,find the shear strain at the edge of this hole when the shear stress is 145MPa. * Mechanics of Materials Chapter 2 Shearing and Bearing HENAN UNIVERSITY SCIENCE TECHNOLOGY Edited by YANG MIN-xian CHAPTER 2 SHEAR AND BEARING §2－1 AVERAGE STRENGTH CALCULATION ABOUT SHEARING AND BEARING OF CONNECTING MEMBERS EXCERCISE LESSONS OF SHEAR AND BEARING §2－1 AVERAGESTRENGTH 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 member is small，but it plays the role of passing loads. Characteristic：It can pass general loads and can be dismounted. P P bolt P P rivet Characteristic: It can pass general loads, but can not be dismounted.for example, the truss in a bridge is connected by it. no gap Characteristic: It can pass torques. m Shaft Key Gear m 2)Characteristics of loads and deformation： n n （Resultant） （Resultant） P P 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. n n （ Resultant ） （Resultant P P ③Shearing plane： The plane along which two parts of the member tend to shift over one another. Such as n– n . ④Internal force on shearing plane： Internal force — Shearing force Q ，its acting line is parallel to the shea