Name of the College : Valliammai Engineering College
Subject : Design of Machine Elements
Subject Code : ME2303
Website : valliammai.co.in
Document Type : Question Bank
Department : Mechanical Engineering
Semester : V
Degree : B.E
Question Bank : https://www.pdfquestion.in/uploads/valliammai.co.in/2835-ME2303-Design%20of%20Machine%20Elements.pdf
Valliammai Design Of Machine Elements Question Paper
Code : ME2303
VALLIAMMAI ENGINEERING COLLEGE
DEPARTMENT OF MECHANICAL
ENGINEERING
QUESTION BANK
Subject code/Name: ME 2303– DE SIGN OF MACHINE ELEMENTS Year/Sem: III / V
Related : Valliammai Engineering College ME2304 Engineering Metrology & Measurement B.E Question Bank : www.pdfquestion.in/2837.html
UNIT- I
(STEADY STRESSES AND VARIABLE STRESSES IN MACHINE MEMBERS)
P AR T – A ( 2 marks)
1. Define: Factor of safety
2. Define endurance limit.
3. What is impact load?
4. What are the various phases of design process?
5. What are the different types of loads that can act on machine components?
6. What are the factors affecting endurance strength. at are the types of variable stresses?
7.Differentiate between repeated stress and reversed stress.
8. What are the types of fracture?
9. Distinguish between brittle fracture and ductile fracture.
10. Define stress concentration and stress concentration factor.
11. Explain size factor in endurance strength. Size factor is used to consider the effect of the size
12. Explain Griffith theory. (Or) State the condition for crack growth.
13. What are the modes of fracture?
14. What are the factors to be considered in the selection of materials for a machine element?
15. What are various theories of failure?
16. List out the factors involved in arriving at factor of safety
17. Give some methods of reducing stress concentration.
18. Explain notch sensitivity.
19. What are the factors that affect notch sensitivity?
20.What is an S-N Curve?
PART –B
1. (a) A piston of a reciprocating compressor has a diameter of 60mm. The maximum pressure on the piston fall is 1.25MN/m2.Assuming the gudgeon pin passing through the small end of the connecting rod can be safely loaded in shear up to 10MN/m2, Calculate the minimum diameter of the gudgeon pin. (8)
(b) Explain with mathematical expressions. Maximum principal stress theory and Von-Mises-Henky theory (8)
2. (a) Determine the diameter of the steel bar, which is a ductile in a nature subjected to an axial load of 60KN and torsional moment of 1600N-m.Use the factor of safety 2.5.E=200GPa. (8)
(b) Explain with mathematical expressions. Maximum shear theory and Venant’s theory (8)
3. A steel member is subjected to a 3-D stress system and resulting principal stress are 120N/mm2 tension, 80N/mm2and 40N/mm2 compression. If the proportional limit of the material in simple tension is 280N/mm2 and its poison’s ratio is O.3.Determine the factor of safety according to (a) Maximum principal stress theory (b) Maximum principal strain theory (c) Maximum shear stress theory. (16)
4. A bolt is subjected to a tensile load of 25KN and a shear load of 10KN.
Determine the diameter of the bolt according to (a) Maximum principal stress theory (b) Maximum principal strain theory (c) Maximum shear stress theory. Assume factor of safety 2.5, Yield point stress in simple tension 300N/mm2, Poisson’s ratio is 0.25. (16)
5. Taking stress concentration in to account find the maximum stress induced when a tensile load of 20KN is applied to (i) A rectangular plate 80mm wide and 12mm thick with a transverse hole of 16mm diameter.
(ii)A stepped shaft of diameters 60mm and 30mm width a fillet radius of 6mm.(16)
6. A circular bar is simply supported with a span of 0.5mand is subjected to a concentrated cyclic load at its midspan. The load varies from a minimum value of20KN to maximum value of 45 KN. The load 3 direction is transverse to the shaft axis. Decide upon the diameter of the bar taking a factor of safety of 1.5 and factor of 0.85 and 0.89 respectively for size effect and surface finish. Take often following values for material properties. Ultimate strength = 650N/mm2, Yield strength = 450N/mm2 Endurance strength =350N/mm2 (16)
7. The bending stress in a machine part fluctuates between a tensile stress of 280N/mm2 and a compressive stress of 140N/mm2. What should be the minimum ultimate tensile strength of this part to carry this fluctuation indefinitely according to (i) Goodman’s formula (ii) Soderberg formula Factor of safety is 1. 75. Assume that the yield point is never likely to be less than 55% of the Ultimate tensile strength or greater than 93 % of it. (16)
8. Determine the thickness of a 120mm wide uniform plate for safe continuous operation if the plate is to be subjected to a tensile load that has a maximum value of 1000N.The properties of the plate materials are as follows. Endurance limit stress is 225MPa and yield point stress is 300MPa.The factor of safety based on yield point may be taken as 1.5. (16)
9. A hot rolled bar of steel is subjected to a torsional load varying from- 150N-m to 450N-m. Determine the required diameter of the bar using a factor of safety of 1.7. Properties of the material may be assumed as follow. Ultimate tensile stress = 450MPa Yield stress = 300MPa (16)
10.A transmission of shaft made C45 steel subjected to a fluctuating torque varying from -100N-m to +500N-m.Also a fluctuating bending moment acts on the shaft which varies from +500N-m to -500Nm. Let the stress concentration factor be 2. The shaft is machined for a factor of safety 1.5.Determine the required diameter of the shaft. (16)
UNIT -II
(DESIGN OF SHAFTS, KEYS AND COUPLINGS)
PART – A ( 2marks )
1.Define the term critical speed.
2. Factor is considered to design a shaft?
3.What is a shaft?
4.What are the types of shafts?
5.What is key?
6.What is key?
7. What are the types of keys?
8. How are sunk key designed?
9. What is the main use of woodruff keys?
10. List the various failures occurred in sunk keys.
11. What is simple torsion?
12.What is simple bending moment?
13.What are the types of rigidity?
14.What are the different measures followed to control the lateral deflection?
15.Define the term critical speed?
16. What is the function of a coupling between two shafts?
17. Under what circumstances flexible couplings are used?
18. What are the purposes in machinery for which couplings are used?
19.What are the types of Rigid coupling?
20. What are the types of Flexible coupling?