lr :ea, I osn CSVTU Course Code:ME B.Tech.( Fifth Semester) Examination, Nov. - Dec. 2o1o Subject: Machine Design-I Branch: Mechanical Engineering Time: Four hours ' MaxMarks:8o Min. Pass Marks: eB Note: All questions are compulsory. Assume suitable data wherever necessary with justification. Use of pSG data book and data sheets are allowed. Drawings to the are to be prepared on separate sheets to be attached with answer sheet. All dimensions are in mm in the figures if otherwise not specified by 1 t<N. Ascertain the saf,ety factor based on theory. (8,8) MPa yield steel and loaded the maximum shear stress (b) Determine the safety factor using Maximum Shear Stress theory and distortion enerry theory, for the state of stress ox = 1O MPa; oy = -rO MPa; Tr,y = o, applied to pure aluminum, Sb = 3o MPa. Draw Mohr's stress circle to show the stress state. . l.c) Acantilever beam made of steel Fe54o ( So, = S4o N/mmz and Sr1 = $2o v N/mms) and subjected to a completely reversed load P of 5 kN in Fig.r(c). The shaft is machined and the reliability is go%2. The factor of safety is z. and the notch sensitivity factor is o.9. Calculate the diameter d for infinite life. Qu.z. Solve the following: (4rtz) (a) Determine the key dimensions for fixing a gear on,a thut of z5mm diameter. rSkW power atZz,a r?m is transmitted from the shaft to the gear. The key material is steel SoC4. O) Desrgn a cotter or lmuckle joint to connect two steel rods of eqgal diameter subjected to an axial tensile force of 5okl'{. Select the material for the joint as plain carbon steel of grade 3oC8. Df?rw the sectional elevation of the joint to a suitable scale showing all the dimensions. Qu,g. Solve any one part of the following: (16) (a) Design the various components of screw jack, Fi8.3(a) for lifting the machine parts on the shop floor ( Screw- steel3oCS, nut - Phosphor bronze grade r, handle - steel goCS and frame - FGzoO ) with a load carrying capacity of roo kN and maximum lifting height of o.5m. The jack is to be manually operated. The load applied at the end of the lever will be 5oo N. (b) Solve the following (8'8) (i) A steel plate subjected to a foree of 5kN and fixed to a channgl by me-ans of three identical bolts, Fig.B(b-i). The bolts are made of plain carbon steel 45CS(Syt = 38o N/mmz) and the factor of safety is 3. Speciff the size ofbolts. (ii) Using the maximum shear stress theory speciS the size oJ the bolts (plain carbon steel 4SC8 Syt = 38o N/m*z) for the following biacket, Fig.S&-ii), P = z5k\[, e = 1oo mm' lr = l5offih, I" = 25mm and factor of safety 2.5. Qu.1. Solve anytwo part of the folloyrrng: i @)The torque wrench,rFig.r(a) is niade from a 35o