STUPIDSID
Answer any one question from Q.1 and Q.2
1(a)
Explain the following
Factors considered for selection of Factor of saftey Standard & Codes
4 M
1(b)
Two shaft are connected by means of cotter joint. The inside diameter of the socket is 0.5 times outer diameter of the socket. The rods are subjected to a axial tensile force of 50kN. The cotter is made of steel (Sut=400MPa) and factor of safety is 4.Assume width of cotter is 5 times of thickness. Calculate : width and thickness of cotter i) on the basis of shear. ii) on the basis of bending failure.
6 M
2(a)
A foot level is 1000 mm from the centre of shaft to the point application of 800 N load.
Find:
Dimenssions of rectangular arm of the foot lever at 60 mm from the centre of shaft assuming width arm as 3 times thickness.
Find:
Dimenssions of rectangular arm of the foot lever at 60 mm from the centre of shaft assuming width arm as 3 times thickness.
4 M
2(b)
With Neat sketch explain design steps of Socket & Spigot type Cotter Joint & write its Applications.
6 M
Answer any one question from Q.3 and Q.4
3(a)
Classify Keys. Prove that Square key is equally strong in Shearing and crushing.
4 M
3(b)
Two 40 mm shaft are connected by unprotected type flange coupling. The no. Of bolts used are 6 on 125 mm bolt PCD. The shaft transmits 30 kW at 350 rpm, for following safe stresses.
Shear stress for shaft - 63 N/mm2 Shear stress for bolt material - 56 N/mm2 Shear stress for flange material - 10 N/mm2 Shear stress of Key material - 46 N/mm2 Crushing stress for key material - 23 N/mm2
Calculate
1) Key Dimensions
2) Flange Dimensions
3) Diameter of Bolts
Calculate
1) Key Dimensions
2) Flange Dimensions
3) Diameter of Bolts
6 M
4
Figure shows shaft layout, supporting two spur gears B and C as shown in figure. The shaft is supporting by two bearing A and D. The pitch circle diameter of gear A and B are 900 mm and 600 mm respectively. The material for shaft is steel with Sut - 770 N/mm2 and Syt ' 580 N/mm2. The factors Kb and Kt of ASME code are 1.5 and 2.0 respectively. Determine the diameter of shaft according to ASME code. Consider the effect of Keyway. Total length of shaft is 2700 mm as shown in figure
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10 M
Answer any one question from Q.5 and Q.6
5(a)(i)
Explain:Draw Goodman & Soderberg diagram with their equations only
2 M
5(a)(ii)
Explain: Emdurance Limit & Notch Sensitivity
2 M
5(b)
A rod of a linkage mechanism made of steel 40Crl(Sut=550MPa)is subjected to a completely reversed axial load OF '1000 kN. The rod is machined on a lathe and the reliability is 90%. There is no stress concentration. Determine the diameter of the rod using a factor of safety of 2 for an infinite conditions. Assume Ka=0.78, kb=0.85, for 90% reliability=0.868.
6 M
6(a)
List and explain in brief the factors for endurance strength.
4 M
6(b)
A machine component is subjected to fluctuating stress that varies form 40 to 100MPa. The corrected endurance limit stress for the machine component is 270MPa. The ultimate tensile strength and yields strength of the material are 600 and 450MPa respectively. Find the factor of safety using
i) Gerber theory
ii) Soderberg line
iii) Goodman line. Also find factor safety against static failure.
i) Gerber theory
ii) Soderberg line
iii) Goodman line. Also find factor safety against static failure.
6 M
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