Question

do fast

Question 2 20 marks e rotating solid steel shaf is simply supported by bearings at poithe force F by a disc (not shown) which meshes with the dise at disc acts vertically as shown in figure where F = 2 kN. The shan A of T 400 Nm. The shaft is machined from steel. a. Using a factor of safety of 3, shaft dia the distortion energy theory and modified-Goodman. bearing shoulders for b. Draw a free hand construction drawing of the arr and is driven the drive mply supported by bearings at points B and C ana D as shown. The force F from ts a torque to point n energy th determine the shaft diameter at various sections bas estimating stress-concentration facton te f meter Assume sharp Assume sharp fillet radii at the th 200 mm T D

Answer 1

200mm F-2K시 100mm Calculations oF bearing Reactions 200 FBD OF shaft for Bending moment calcula thions 100-12k시 200 200MN mm tHence the shaft is subjected to max bending moment - 200 KN-mm Iso through out the shaFt a constant torque oF 400 N-m is acting which turns the bending stress completely reversed Al kts* 22 kt ะ 27 For sharp fillet radii 9 0.80.9 Fatigue stress concent ration factor hh" 1+0.9 x(22-1):2-08.

Bending stresses Mmin 200xlo3 N-mm Ob)max 32x 200 Xlo 2037183 212 d3 o min2037133 872 d8. 3 neodamp 2037183 212 Torsional shear stress Tmax tmin 16X400x10 2037183 272 2 Cmean2037183 272 2 Tamp- Using distortion energy theoay Mean Equivalent stressKpn)2+ 3(KF Tm)2 Mean Equivalent stress(Kform)t 3(Kfs Tm)2 (2.08x 2037 183 272)2 (24×0)2+3 / = 733 9290 257 d3 4889239.853 d3 For steel Sut-560MPa Se 0.5Sut = 280 Mra. Assuming cotracted limit Of endurance280MPa

By Goodman's crterta Sut FOS 4889239.853+ 73392 90.257 d3x 280 d3x5 60 d Ξ 45.094 mm