工程力學(xué)雙語(yǔ)課件ch12-Shear stresse

1、 the smaller the torque with the maximum absolute value in the shaft is, the more reasonable it is. So wheel 1 must be replaced with wheel 2. After transposition, torque diagram of the shaft is shown in the figure. Under this case,the maximum diameter of the shaft is 75mm。 T (kNm 2.814 x 4.21 36 Cha

2、pter 3 Exercises 1. In a gear-box, why is the shaft with a slow speed thicker than that with a height speed？ 2. When the shearing stress and the normal stress coexist in an element, is the theorem of the conjugate shearing stress amenable? Why? 3. For a hollow circular tube of Al, the outside diamet

3、er is D100mm， the inside diameter is d80mm, and the length is L2.5m. The Shearing elastic modulus is G28GPa. If a force couple is acted on both ends of the circular tube and results in the pure torsion, try to determine the torsional angle when the maximum shearing stress is 50MPa. For the solid sha

4、ft of Al subjected to the same force couple and having the same maximum shearing stress, what is the diameter D2? Determine the ratio of the weight of the hollow tube to that of the solid shaft. Solution: TL t maxWt L 2t maxL 2 ´ 50 ´ 2.5 ° j = = = = = 5 . 12 GI p GI p GD 28 ´100 T T = Wt1 Wt Þ pD13 pD 3 = (1 - a 4 16 16 D1 = D3 1 - a 4 = 1003 1 - 0.84 = 83.9mm As the two have the same material and the same length, the ratio of weights is equal to the ratio of cross-s