Assignment-2
Q1.Design a double riveted lap joint for M.S Plates 10 mm thick. Calculate the efficiency of
the joint. The permissible stresses are: σt = 100 MPa,ζs = 70 MPa, σc= 130 Mpa .
Q2.Two steel plates 12.5 mm thick are required to carry a tensile load of 400 kN in double
cover plate butt joint. Calculate the width of the plate if it is not to be weakened by more
than one rivet hole. Design the butt joint completely and show dimension on a sketch. The
Ultimate values of strength are follows:
Plate in tension-480MPa
Rivet in shear-390 MPa
Plate and rivet in crushing -735 MPa
Use the factor of safety of 4.5 in all modes failure
Q3. A machine shaft is supported in bearings placed at a distance of 700 mm. The shaft
carries a 500 mm dia. pulley at a distance of 200 mm on right of right hand bearing and a spur
gear 200 mm dia. at a distance of 250 mm on the right of left hand bearing.15 kW of power is
supplied to spur gear at 600 r.p.m. and taken off at the pulley on which belt is mounted
making an angle of 60 0 with the horizontal. The ratio of the belt tensions is 3:1 and the pulley
weights 800N.The gear meshes with another gear located directly above the shaft.The
materials of the shaft is chosen with σu = 500 MPa and σY = 310 MPa. Determine the dia. of
the shaft.
Q4. A solid machine shaft 40 mm in dia. Transmit a torque of 1000 N-m. A square key is used
whose one side is equal to 0.20 times the dia. of shaft and whose length is equal to 1.2times the shaft
dia. Find the dimensions of the key and check the key for its induced shearing and crushing
stresses. Obtain the factor of safety of the key in shear and crushing when yield stresses in shearing
and crushing are 300 N/mm2 and 400 N/mm2 respectively.