中国石油大学工程力学课件tm402mat2012.ppt

* Kylinsoft MOM-2-* (4) 确定BC段直径: 由扭转强度条件得: 由扭转刚度条件得 取d2 = 75mm 7024N.m 4214.4 T 400 200 N1 N2 N3 A B C * Kylinsoft MOM-2-* 2.7 Statically Indeterminate Torsion 解： (1)解除B端约束，建立静定基本体系(Released form) Example 2-5 已知M0 = 10kN·m，试绘扭矩图。 m0 m0 A C D B a a a A C D B m0 m0 a a a mB (3) Force-displacement relations (2) Equation of compatibility 补充方程： 解得： * Kylinsoft MOM-2-* m0 m0 A C D B a a a A C D B m0 m0 a a a mB (4) 由静力方程，得: mA=mB=m0/3 (5) 作扭矩图，由图可知CD段为危险段。 2m0/3 m0/3 T x * Kylinsoft MOM-2-* A B l m m f2 f1 a a f b b Example 2-6 圆轴上有AB两个凸缘，受力偶矩m作用变形后焊上圆筒，在解除力矩m。设轴和筒的抗扭刚度分别是G1IP1和 G2IP2 ，试求轴内和筒内的扭矩。 轴受扭矩T1，筒受扭矩T2，且 T1-T2=0 解除m后，轴和筒的扭转角分别为f1和f2，有： 补充方程： 解得： 焊接前轴在m作用下的扭转角： * Kylinsoft MOM-2-* 2.8 Strain Energy (扭转应变能) L f m m o f m f m strain energy strain energy density * Kylinsoft MOM-2-* 作业 作业 P58-2.1(b)、 P59-2.11、 P59-2.14 * Kylinsoft MOM-2-* 制作群 素材收集 海盗船长 多媒体制作 海盗船长 总编辑 海盗船长 审核 海盗船长 总策划 海盗船长 赞助 海盗船长 * Kylinsoft * Kylinsoft MOM-2-* Chapter 2 Torsion 第二章 扭转 海盗船长 * Kylinsoft MOM-2-* 2.1 Introduction Torsion refers to the twisting of a straight bar when it is loaded by moments (or torques) that tend to produce rotation about the longitudinal axis of the bar. 汽车传动轴 * Kylinsoft MOM-2-* * Kylinsoft MOM-2-* 2.2 Transmission of Power by Circular Shafts T T Shaft Motor A rotary speed: n (rpm) power of the motor: N (kW) If power is expressed in horsepower (hp), the torque will be 1 Transmitted torque: T (N·m) * Kylinsoft MOM-2-* n m n T 2 Internal Torque and Torque Diagram cross-section method for Internal Torque n m x n T m m n n Equilibrium Smx = 0 T - m = 0 T = m sign convention for Internal Torque by the right-hand rule * Kylinsoft MOM-2-* Example 2-1 A steel shaft is driven at A by a motor that transmits NA=50hp. The gears at B, C and D drive machinery requiring pow